Voltage-Ampere Characteristics of Diode Questi...

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Voltage-Ampere Characteristics of Diode Questions and Answers by Manish 4-5 minutes

This set of Analog Circuits Multiple Choice Questions & Answers (MCQs) focuses on “Voltage-Ampere Characteristics of Diode – 1”. 1. The abbreviation PIV in the case of a diode stands for a) Peak Inferior Voltage b) Problematic Inverse Voltage c) Peak Inverse Voltage d) Peak Internal Voltage View Answer Answer: c Explanation: PIV stands for Peak Inverse Voltage. It is the maximum reverse bias voltage which a diode can bear without breakdown. 2. What is mean by PIV rating of a diode a) Maximum reverse bias potential which can be applied across a diode without breakdown b) Maximum forward bias potential which can be applied across a diode without breakdown

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Voltage-Ampere Characteristics of Diode Questi...

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c) Minimum potential required by a diode to reach conduction state d) Maximum power allowable to a diode View Answer Answer: a Explanation: PIV rating indicate the maximum allowable reverse bias voltage which can be safely applied to a diode. If reverse potential is greater than PIV rating then the diode will enter reverse breakdown region. 3. The voltage after which the diode current exponentially increases with forward bias is NOT known as a) Offset voltage b) Threshold potential c) Firing potential d) Peak forward voltage View Answer Answer: d Explanation: The voltage after which a diode increases rapidly is known as offset voltage, threshold voltage, firing potential and cut-in voltage. Beyond this voltage the forward bias voltage overcomes the potential barrier and rapid conduction occurs. 4. The diode current equation is not applicable in a) Forward biased sate b) Reverse biased state c) Unbiased state d) It is applicable in all bias sates View Answer 2 of 5

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Voltage-Ampere Characteristics of Diode Questi...

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Answer: d Explanation: Diode equation is I=I0 (e(qV/kT)-1). It is applicable in all bias condition that is forward, reverse and unbiased states. 5. Emission coefficient of Germanium is a) 1 b) 1.1 c) 1.5 d) 2 View Answer Answer: a Explanation: Emission coefficient or ideality factor s the effect of recombination taking place in the depletion region. The range of factor is from 1 to 2.For Germanium it is 1. 6. The ideality factor of Silicon is a) 1 b) 2 c) 1.3 d) 1.7 View Answer Answer: b Explanation: Emission coefficient or ideality factor s the effect of recombination taking place in the depletion region. The range of factor is from 1 to 2.For silicon it is 2. 7. The value of voltage equivalent of temperature at room temperature(27oC) a) 26mV 3 of 5

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Voltage-Ampere Characteristics of Diode Questi...

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b) 36mV c) 0.26mV d) 260mV View Answer Answer: a Explanation: Voltage equivalent of temperature VT is equal to the product of boltzman constant and temperature. At room temperature it is 26mV. 8. What happens to cut-in voltage when temperature increases? a) Cut-in voltage increases b) Cut-in voltage decreases d) Cut-in voltage either increases or decreases e) Cut-in voltage doesn’t depend on temperature View Answer Answer: b Explanation: As temperature increases conductivity of a semiconductor increases. The diode conducts smaller voltage at larger temperature. Therefore, cut-in voltage decreases. 9. When temperature increases reverse saturation current a) Increases b) Decreases c) Doesn’t depend on temperature d) Either increases or decreases View Answer Answer: a Explanation: As temperature increases conductivity of a 4 of 5

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Voltage-Ampere Characteristics of Diode Questi...

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semiconductor increases. Reverse saturation current increases as temperature increases. Sanfoundry Global Education & Learning Series – Analog Circuits. To practice all areas of Analog Circuits, here is complete set of 1000+ Multiple Choice Questions and Answers.

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Analog Circuits Interview Questions and Answers

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Analog Circuits Interview Questions and Answers by Manish 7-9 minutes

This set of Analog Circuits Interview Questions and Answers focuses on “Voltage-Ampere Characteristics of Diode 2”. 1. Which of the following graph represents the I-V characteristics of real diode

a)

b)

c) 1 of 11

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Analog Circuits Interview Questions and Answers

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d) View Answer Answer: d Explanation: First graph represents constant voltage drop model of diode. In this mode diode assumes as a perfect insulator on reverse bias. On forward bias up to cut-in voltage it assumes to be an insulator and after it becomes perfect conductor. Second graph represents ideal diode that is in forward bias it is a perfect conductor and in reverse bias it is perfect insulator. Third graph represents piecewise linear mode of diode. This assumption is very close to constant voltage drop model except the fact that after cut-in voltage instead of perfect insulator diode is assumed as a ohmic device. The fourth graph represents real diode. The diode in real life is similar to the characteristics. That is after cut-in voltage graph is exponential and in reverse bias mode current is in micro or nano ampere range. 2. Which of the following I-V characteristics represents a typical Si diode

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Analog Circuits Interview Questions and Answers

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a)

b)

c)

d) View Answer Answer: b Explanation: The second graph denotes a Si diode because the cut-in voltage is 0.7V and after this the current is exponential. Also in reverse bias there is a nano ampere range current it must also be ed. Therefore, second

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Analog Circuits Interview Questions and Answers

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option is the best. 3. Which of the following graph represents a typical Ge diode

a)

b)

c)

d) View Answer Answer: a Explanation: The first graph denotes a Si diode because the

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Analog Circuits Interview Questions and Answers

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cut-in voltage is 0.7V and after this the current is exponential. Also in reverse bias there is a micro ampere range current it must also be ed. Therefore, first option is the best. 4. Which of the following graph represent a zener diode which is voltage rated as “VZ”.

a)

b)

c)

d) 5 of 11

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Analog Circuits Interview Questions and Answers

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View Answer Answer: b Explanation: Voltage rating is the voltage at which reverse breakdown occurs. Voltage rating of a zener diode indicates the voltage beyond which current increases rapidly. Beyond this point increase in reverse bias voltage will only reflect on current which means voltage drop beyond this point is almost constant. At forward bias zener diode behaves as a normal diode. So appropriate graph is second. 5. Which of the following statement is false for a zener diode voltage rated as “VZ “ a) Reverse breakdown occurs at VZ b) Forward breakdown occurs at VZ c) Zener diode is a heavily doped diode d) Usually operates in reverse bias mode View Answer Answer: b Explanation: Voltage rating is the voltage at which reverse breakdown occurs. Voltage rating of a zener diode indicates the voltage beyond which current increases rapidly. Beyond this point increase in reverse bias voltage will only reflect on current which means voltage drop beyond this point is almost constant. This phenomenon holds the key role in the working of zener diode as a voltage regulator. Zenor diode is a heavily doped diode because for zenor breakdown we need a narrow junction. It operates in reverse bias mode. In forward bias mode it operates as a normal diode. 6. Voltage rating of a zener diode denoted 6 of 11

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Analog Circuits Interview Questions and Answers

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a) Reverse breakdown voltage b) Forward breakdown voltage c) Voltage at which current is maximum d) maximum forward voltage which a diode can withstand View Answer Answer: a Explanation: Voltage rating of a zener diode indicates the voltage beyond which current increases rapidly. Beyond this point increase in reverse bias voltage will only reflect on current which means voltage drop beyond this point is almost constant. This phenomenon holds the key role in the working of zener diode as a voltage regulator. 7. Knee current in the case of zener diode implies a) Forward bias current beyond which I-V characteristics is a straight line b) Reverse bias current above which I-V characteristics is a straight line c) Forward cut-in current beyond which current is directly proportional to voltage d) Maximum allowable reverse bias current through a zener diode View Answer Answer: b Explanation: Knee current indicates the current above which reverse characteristics is a straight line. That is the relationship between current and voltage beyond this point will be directly proportional and this is very useful for solving real life problems.

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Analog Circuits Interview Questions and Answers

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8. Which of the following graph represents I-V characteristics of an ideal diode

a)

b)

c)

d) View Answer Answer: b Explanation: First graph represents constant voltage drop model of diode. In this mode diode assumes as a perfect insulator on reverse bias. On forward bias up to cut-in voltage it assumes to be an insulator and after it becomes perfect conductor. Second graph represents ideal diode that is in forward bias it is a perfect conductor and in

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Analog Circuits Interview Questions and Answers

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reverse bias it is perfect insulator. Third graph represents piecewise linear mode of diode. This assumption is very close to constant voltage drop model except the fact that after cut-in voltage instead of perfect insulator diode is assumed as a ohmic device. The fourth graph represents real diode. The diode in real life is similar to the characteristics. That is after cut-in voltage graph is exponential and in reverse bias mode current is in micro or nano ampere range. 9. Which of the following I-V characteristics represents the constant voltage drop model of diode

a)

b)

c)

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d) View Answer Answer: a Explanation: First graph represents constant voltage drop model of diode. In this mode diode assumes as a perfect insulator on reverse bias. On forward bias up to cut-in voltage it assumes to be an insulator and after it becomes perfect conductor. Second graph represents ideal diode that is in forward bias it is a perfect conductor and in reverse bias it is perfect insulator. Third graph represents piecewise linear mode of diode. This assumption is very close to constant voltage drop model except the fact that after cut-in voltage instead of perfect insulator diode is assumed as a ohmic device. The fourth graph represents real diode. The diode in real life is similar to the characteristics. That is after cut-in voltage graph is exponential and in reverse bias mode current is in micro or nano ampere range. 10. Which of the following statement about a Si diode is true a) Cut-in voltage is always higher than reverse breakdown voltage b) Reverse saturation current is in the order of mA c) Cut-in voltage is 1V

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Analog Circuits Interview Questions and Answers

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d) Reverse scale current is in the order of nA View Answer Answer: d Explanation: Cut-in voltage of Si diode is 0.7V but reverse breakdown voltage is almost 50V for a Si diode. So clearly cut-in voltage is much less than reverse breakdown voltage. Reverse saturation current is in the order of nano amperes. Scale current is another name of saturation current. It is named as scale current because saturation current is directly proportional to cross sectional area of diode. Sanfoundry Global Education & Learning Series – Analog Circuits. To practice all areas of Analog Circuits for Interviews, here is complete set of 1000+ Multiple Choice Questions and Answers.

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Diode Characteristic Equation - Analog Circuits...

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Diode Characteristic Equation Analog Circuits Questions and Answers by Manish 5-6 minutes

This set of Analog Circuits Multiple Choice Questions & Answers (MCQs) focuses on “Characteristic Equation of Diode 1”. 1. Calculate the forward bias current of a Si diode when forward bias voltage of 0.4V is applied, using characteristic equation of diode. The reverse saturation current is 1.17 x 10-9 A. Thermal voltage is 25.2 mV. a) 9.156mA b) 8.23mA c) 1.256mA d) 5.689mA View Answer Answer: a Explanation: Equation for diode current I=I0×(e(V/ηVT)-1) where I0 = reverse saturation current η = ideality factor VT = thermal voltage

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Diode Characteristic Equation - Analog Circuits...

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V = applied voltage Since in this question ideality factor is not mentioned it can be taken as one. I0 = 1.17 x 10-9A, VT = 0V, η = 1, V = 0.4V

Therefore, I= 1.17×10-9xe0.4/0.025 -1 = 9.156mA 2. Calculate thermal voltage for a temperature of 25oC. a) 0V b) 0V c) 0.026V d) 0.25V View Answer Answer: b Explanation: Thermal voltage VT is given by k T/q Where k is the boltzman constant and q is the charge of electron. This can be reduced to VT = TK/11600 Therefore, VT at T= 25+273=298 is 298/11600 = 0V 3. Calculate the reverse saturation current of a diode if the current at 0.2V forward bias is 0.1mA at a temperature 25 oC and ideality factor is 1.5 a) 5.06x 10-9 A b) 5.06x 10-8 A c) 5.06x 10-7 A d) 5.06x 10-10 A View Answer Answer: c Explanation: Equation for diode current I=I0×(e(V/ηVT ) -1) where I0 = reverse saturation current η = ideality factor VT = thermal voltage V = applied voltage 2 of 7

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Diode Characteristic Equation - Analog Circuits...

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Here, I = 0.1mA, η = 1.5, V= 0.2V, VT = TK/11600 Therefore, VT at T= 25+273=298 is 298/11600 = 0V.

Therefore, reverse saturation current 4. Find the applied voltage on a forward biased diode if the current is 1mA and reverse saturation current is 10-10A. Temperature is 25 oC and take ideality factor as 1.5 a) 0.658V b) 0.726V c) 0.526V d) 0.618V View Answer Answer: d Explanation: Equation for diode current I=I0×(e(V/ηVT)-1) where I0 = reverse saturation current η = ideality factor VT = thermal voltage V = applied voltage VT at T= 25+273=298 is 298/11600 = 0V, η = 1.5, I = 1mA, I0 = 10-10A

5. Find the temperature at which a diode current is 2mA for a diode which has reverse saturation current of 10-9 A and ideality factor is 1.4, the applied voltage is 0.6V forward bias. a) 69.65oC b) 52.26oC c) 25.23oC d) 70.23oC View Answer

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Diode Characteristic Equation - Analog Circuits...

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Answer: a Explanation: Equation for diode current I=I0×(e(V/ηVT)-1) where I0 = reverse saturation current η = ideality factor VT = thermal voltage V = applied voltage I0 = 10-9A, η = 1.4, V =0.6V, I = 2mA We know thermal voltage VT = TK/11600 .Therefore, TK = VTx11600 = 0x11600 = 342.65K = 69.65oC. 6. Consider a silicon diode with η=1.2. Find change in voltage if the current changes from 0.1mA to 10mA. a) 0.154V b) 0.143V c) 0.123V d) 0.165V View Answer Answer: b Explanation: Equation for diode current I=I0×(e(V/ηVT)-1) where I0 = reverse saturation current η = ideality factor VT = thermal voltage V = applied voltage η = 1.2, I2 = 10mA, I1 = 0.1mA and take VT = 0.026V

7. If current of a diode changes from 1mA to 10mA what will be the change in voltage across the diode. The ideality factor of diode is 1.2 a) 0.718V b) 7.18V c) 0V d) 0.00728V View Answer 4 of 7

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Diode Characteristic Equation - Analog Circuits...

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Answer: c Explanation: η = 1.2, I2 = 10mA, I1 = 1mA and take VT = 0.026V . 8. What will be the ratio of final current to initial current of a diode if voltage of a diode changes from 0.7V to 872.5mV. Take ideality factor as 1.5 a) 90.26 b) 52.36 c) 80.23 d) 83.35 View Answer Answer: d Explanation: η = 1.5, ΔV = 0.8725V and take VT = 0.026V

9. What will be the current I in the circuit diagram below. Take terminal voltage as 0.7V and I0 as 10-12A.

a) 2.4mA b) 0.9mA c) 1mA d) 4mA View Answer Answer: a

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Diode Characteristic Equation - Analog Circuits...

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Explanation: Let VD be the voltage of diode, then by Kirchoff’s loop rule 3V = VD + IR1 This method of assumption contains small error but it is the simplest method. Let VD be 0.7V. Now the current I = (3-0.7)/1k = 2.3mA. Now the diode voltage for 2.3mA VD = VT ln(I/I0 ) = 0.026 x ln((2.3×10(-3))/10(-12) ) = 0.560. Now the current becomes (3-0.560)/1000 = 2.44mA. 10. Find current I through the circuit using characteristic equation of diode. The terminal voltage of each diode is 0.6V. Reverse saturation current is 10-12A.

a) 0.845mA b) 1.892mA c) 2.359mA d) 3.012mA View Answer Answer: b Explanation: Let VD be the voltage of diode, then by Kirchoff’s loop rule 3V = 2VD + IR1 This method of assumption contains small error but it is the simplest method. Let VD be 0.6V. Now the current I = (3-1.2)/1k = 2.8mA. 6 of 7

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Diode Characteristic Equation - Analog Circuits...

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The VD for 2.8mA is 0.554V. Hence current is (3-(2×0.554))/1k =1.892mA. Sanfoundry Global Education & Learning Series – Analog Circuits. To practice all areas of Analog Circuits, here is complete set of 1000+ Multiple Choice Questions and Answers.

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Analog Circuits Questions and Answers for Freshers

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Analog Circuits Questions and Answers for Freshers by Manish 6-7 minutes

This set of Analog Circuits Questions and Answers for Freshers focuses on “Characteristic Equation of Diode 2”. 1. Find the current I if each diodes are identical and assume two diodes are identical. Voltage V = 0.8V and let the reverse saturation current be 10-9A.

a) 4.8mA b) 3.2mA c) 2.5mA d) 7mA View Answer Answer: a Explanation: Since both diodes are identical VD = 0.6/2 = 0.3V Equation for diode current

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Analog Circuits Questions and Answers for Freshers

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where I0 = reverse saturation current η = ideality factor VT = thermal voltage V = applied voltage Since in this question ideality factor is not mentioned it can be taken as one. Take VT as 0.026 which is the standard value. Hence current through one diode is 10-9x(e0.3/0.026) = 4.8mA. 2. Find voltage Vout if the reverse saturation current of the diode is 1.1×10-8A and cut-in voltage of diode is 0.6V and assume the temperature as 25oC.

a) 0.235V b) 0.3148V c) 0.456V d) 0.126V View Answer Answer: b Explanation: Equation for diode current where I0 = reverse saturation current η = ideality factor VT = thermal voltage V = applied voltage Since in this question ideality factor is not mentioned it can be taken as one. Take VT as its standard value 0.026V.

. 3. The current Ix in the circuit is 1mA then find the voltage

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Analog Circuits Questions and Answers for Freshers

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across diode D1. The resistance R1 is 1K. Assume the reverse saturation current is 10-9A. Voltage across resistor in this condition was 0.4V. Take VT of diode as0.026V.

a) 2.3mA b) 3.2mA c) 5.2mA d) 4.6mA View Answer Answer: c Explanation: Since voltage drop across diode is 0.4V current through resistor is 0.4/1k = 0.4mA Current through diode where I0 = reverse saturation current η = ideality factor VT = thermal voltage V = applied voltage Since ideality factor is not given take it as one. Current through diode I= 10-9 x (e0.4/0) = 4.8mA Total current =4.8mA+0.4mA = 5.2mA. 4. Find the current Ix if the voltage across the diode is 0.5V. The reverse saturation current of diode 10-11 , Cut-in voltage of diode is 0.6V. Assume temperature at which diode operates is 25oC. The resistance R1=2K.

a) 3.97mA

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b) 4.51mA c) 2.45mA d) 3.28mA View Answer Answer: d Explanation: Since voltage drop across diode is 0.5V current through resistor is 0.5/2k = 0.25mA Current through diode where I0 = reverse saturation current η = ideality factor VT = thermal voltage V = applied voltage Since ideality factor is not given take it as one. Current through diode I= 10-11 x (e0.5/0) = 3.03mA Total current =3.03mA+0.25mA = 3.28mA. 5. If the current I is 2mA then find the temperature at which diode operates. The cut-in voltage of diode is 0.6V. The reverse saturation current of diode is 10-9A. Resistance R is 1.3K.

a) 46.23oC b) 50.47oC c) 60.26oC d) 56.89oC View Answer Answer: a Explanation: Equation for diode current

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Analog Circuits Questions and Answers for Freshers

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where I0 = reverse saturation current η = ideality factor VT = thermal voltage V = applied voltage Since in this question ideality factor is not mentioned it can be taken as one. VD = 3-(2mAx1.3k) = 0.4V

. 6. If temperature increases 10oC the ratio of final reverse saturation current to initial reverse saturation current a) 1 b) 2 c) 1.5 d) 3 View Answer Answer: b Explanation: The equation relating final reverse saturation current (Io2 ) to initial reverse saturation current (Io1 ) is given by Io2 = 2(ΔT/10)Io1 Where ΔT is temperature change Ratio will be 2(ΔT/10) = 21 =2.

7. The reverse saturation current of a diode at 25oC is 1.5 x 10-9A and what will be reverse current at temperature 30oC a) 3 x 10-9A b) 2 x 10-9A c) 2.12 x 10-9A d) 1.5 x 10-9A View Answer 5 of 8

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Answer: c Explanation: The equation relating final reverse saturation current (Io2) to initial reverse saturation current (Io1 ) is given by Io2 = 2(ΔT/10)Io1 Where ΔT is temperature change

Here ΔT = 5, Therefore, Io2 = 25/10 Io1 =1.414×1.5 x 10-9A = 2.121 x 10-9A.

8. How much times reverse saturation current will increase if temperature increases 15oC a) 2.52 b) 4.62 c) 4.12 d) 2.82 View Answer Answer: d Explanation: The equation relating final reverse saturation current (Io2) to initial reverse saturation current (Io1) is given by Io2 = 2(ΔT/10)Io1 Where ΔT is temperature change Ratio is 215/10 = 2.82. 9. If the Vin of the circuit the circuit is 2V and resistor have a resistance of 1K and cut-in voltage of diode is 0.7V. Reverse saturation current is 10-8A. Temperature at which diode operates is 30oC.The Vout is close to a) 0.256V b) 0.306V c) 0.215V d) 0.456V

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View Answer Answer: b Explanation: Let VD be the voltage of diode, then by Kirchoff’s loop rule Vin = VD + IR1 This method of assumption contains small error but it is the simplest method. Let VD be 0.7V. Now the current I = (2-0.7)/1k = 1.3mA. Now the diode voltage for 1.3mA VD = VT ln(I/I0 ) = 0.026 x ln((1.3×10-3)/10-8 ) = 0.306. Therefore, voltage across diode will be close to 0.306V. 10. Let the Vin be -5V and resistance R1 is 5K and the cutin voltage of the diode is 0.7V. What will be the voltage Vout? Take reverse saturation current as 10-8A and operating temperature as 25oC. a) 0V b) -4.5V c) -5V d) -3.2V View Answer Answer: c Explanation: Since diode is in reverse bias mode voltage across diode will be almost same as applied voltage. Since the current in the circuit is in micro amperes voltage drop at R1 is negligible. Sanfoundry Global Education & Learning Series – Analog Circuits. To practice all areas of Analog Circuits for Freshers, here is 7 of 8

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Analog Circuits Questions and Answers for Freshers

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complete set of 1000+ Multiple Choice Questions and Answers.

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Resistance Level - Analog Circuits Questions an...

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Resistance Level - Analog Circuits Questions and Answers by Manish 4-5 minutes

This set of Analog Circuits Multiple Choice Questions & Answers (MCQs) focuses on “Resistance Level”. 1. What is quiescent point or Q-point? a) Operating point of device b) The point at which device have maximum functionality c) The point at which current equal to voltage d) The point of V-I graph where slope is 0.5 View Answer Answer: a Explanation: Quiescent point of a device represents operating point of a device. For a diode quiescent point is determined by constant DC current through the diode. 2. The reciprocal of slope of current-voltage curve at Q-point gives a) AC resistance b) Nominal resistance c) Maximum dynamic resistance d) Minimum impedance

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Resistance Level - Analog Circuits Questions an...

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View Answer Answer: a Explanation: Reciprocal of slope of I-V graph at q-point gives AC or dynamic resistance. The inverse of slope will be change in voltage by change in current which is known as dynamic resistance. 3. As slope of I-V graph at Q-point increase ac resistance will a) Increase b) Decrease c) Either increase or decrease d) Neither increase nor decrease View Answer Answer: b Explanation: Slope of I-V graph at q-point is reciprocal of dynamic or AC resistance. Therefore, as slope increases resistance decreases. 4. Static resistance of a diode is a) Maximum resistance of device b) Resistance at q-point c) Resistance at static points d) Minimum resistance of a diode View Answer Answer: b Explanation: Static or DC resistance of a diode is the resistance offered by a diode at its q-point. DC resistance represents steady state. That is, it is calculated by treating current and voltage as constants. 2 of 6

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Resistance Level - Analog Circuits Questions an...

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5. Average AC resistance and dynamic resistance are a) Always Equal b) Never equal c) Both represents same quantity d) calculated from V-I graph View Answer Answer: d Explanation: Average AC resistance and dynamic or AC resistance are not exactly same. They both measures the resistance in a different way. AC resistance is slope of the tangent of the curve of characteristic graph at Q-point. But average AC resistance is measured by measuring the slope of straight line between limits of operation. 6. After cut-in voltage AC resistance of diode a) Slightly decreases b) Decreases exponentially c) Slightly increases d) Increases exponentially View Answer Answer: b Explanation: After cut-in voltage current exponentially increases with small increase in voltage. This will considerably reduce resistance. 7. DC resistance of diode is measured at a) Knee current b) Cut-in voltage c) Q-point d) Reverse breakdown point 3 of 6

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Resistance Level - Analog Circuits Questions an...

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View Answer Answer: c Explanation: Static or DC resistance of a diode is the resistance offered by a diode at its q-point. DC resistance represents steady state. That is, it is calculated by treating current and voltage as constants. 8. Determine DC resistance of a diode described by characteristic graph at ID = 10mA.

a) 9 Ω b) 11.11 Ω c) 10.10 Ω d) 13.13 Ω View Answer Answer: a Explanation: Static or DC resistance is the resistance of a diode at its operating point. That is DC resistance = 0.9/10mA =9Ω. 9. For a diode, at 10mA DC resistance is 70Ω. The voltage corresponding to 10mA will be a) 0.5V

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b) 0.6V c) 0.7V d) 0.8V View Answer Answer: c Explanation: Static or DC resistance is the resistance of a diode at its operating point. Resistance = voltage/current Therefore, voltage = current x resistance = 10mA x70 =0.7V 10. Calculate resistance of a diode at VD = -10V from the characteristic graph given below

a) 1MΩ b) 10MΩ c) 15MΩ d) 5MΩ View Answer Answer: b Explanation: Static or DC resistance is the resistance of a diode at its operating point. Static resistance at -10V = 10V/current at -10V =10/1µA =10MΩ. 5 of 6

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Sanfoundry Global Education & Learning Series – Analog Circuits. To practice all areas of Analog Circuits, here is complete set of 1000+ Multiple Choice Questions and Answers.

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Ideal Diode Model - Analog Circuits Questions and Answers by Manish 5-6 minutes

This set of Analog Circuits Multiple Choice Questions & Answers (MCQs) focuses on “Ideal Diode Model – 1”. 1. In ideal diode model diode in forward bias is considered as a a) Resistor b) Perfect conductor c) Perfect insulator d) capacitor View Answer Answer: b Explanation: In ideal diode model the diode is considered as a perfect conductor in forward bias and perfect insulator in reverse bias. That is voltage drop at forward bias is zero and current through the diode at reverse bias is zero. 2. In ideal diode model diode in reverse bias is considered as a a) Resistor b) Perfect conductor

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c) Perfect insulator d) capacitor View Answer Answer: c Explanation: In ideal diode model the diode is considered as a perfect conductor in forward bias and perfect insulator in reverse bias. That is voltage drop at forward bias is zero and current through the diode at reverse bias is zero. 3. Voltage drop produced by a diode at forward bias in ideal diode model is equal to a) 0.7V b) 0.3V c) 1V d) 0V View Answer Answer: d Explanation: In ideal diode model the diode is considered as a perfect conductor in forward bias and perfect insulator in reverse bias. That is voltage drop at forward bias is zero and current through the diode at reverse bias is zero. 4. The current I through the circuit if we consider diode in ideal diode model

a) 3mA b) 3A

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c) 1A d) 0.4mA View Answer Answer: a Explanation: In ideal diode model the diode is considered as a perfect conductor in forward bias and perfect insulator in reverse bias. That is voltage drop at forward bias is zero and current through the diode at reverse bias is zero. Since diode is forward biased current I = (3V/1K) = 3mA. 5. The voltage across the diode Vout if Vin is -5V and resistance is 10K is

a) -5V b) 0V c) -2.5V d) 2.5V View Answer Answer: a Explanation: In ideal diode model the diode is considered as a perfect conductor in forward bias and perfect insulator in reverse bias. That is voltage drop at forward bias is zero and current through the diode at reverse bias is zero. Since diode is reverse bias no current flows through the circuit so entire voltage appears on diode.

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6. The current I through the circuit I if voltage v is -3V is

a) 0A b) 3A c) 1.5A d) 6A View Answer Answer: a Explanation: In ideal diode model the diode is considered as a perfect conductor in forward bias and perfect insulator in reverse bias. That is voltage drop at forward bias is zero and current through the diode at reverse bias is zero. Since diode is reverse bias no current will flow through the circuit. 7. If current source produces a current of 1mA and resistance R is 3K then voltage across the resistor is

a) 0V b) 1V c) 3V d) 1.5V View Answer Answer: a Explanation: In ideal diode model the diode is considered as a perfect conductor in forward bias and perfect insulator in reverse bias. That is voltage drop at forward bias is zero 4 of 7

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and current through the diode at reverse bias is zero. Since current forward biases the diode it acts as a conductor so current through resistor is zero so voltage is zero. Therefore, voltage across resistor is zero. 8. If resistance R1 is 10K, V2 = 2V, V1 = 3V then the current I through the circuit will be

a) 0.3mA b) 0.6mA c) 0.7mA d) 0.1mA View Answer Answer: d Explanation: In ideal diode model the diode is considered as a perfect conductor in forward bias and perfect insulator in reverse bias. That is voltage drop at forward bias is zero and current through the diode at reverse bias is zero. Since both voltage is reverse bias to diode the diode will disappear from the circuit. Then effective voltage becomes 3-2 = 1V so current is 1/10K = 0.1mA. 9. If resistance R1 is 10K, V2 = – 2V, V1 = 3V then the current I through the circuit will be

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a) 0.2mA b) 0A c) 0.5mA d) 0.3mA View Answer Answer: d Explanation: In ideal diode model the diode is considered as a perfect conductor in forward bias and perfect insulator in reverse bias. That is voltage drop at forward bias is zero and current through the diode at reverse bias is zero. The voltage V2 forward biases the diode so in effect V2 VAnishes. Also the V1 reverse bias to diode so it will not through diode. Therefore, effective current will be (3V/10K) = 0.3mA. 10. What will be the voltage Vout if VA = 3V and VB = -5V?

a) 5V b) 3V c) 2V d) 0V View Answer

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Answer: b Explanation: In ideal diode model the diode is considered as a perfect conductor in forward bias and perfect insulator in reverse bias. That is voltage drop at forward bias is zero and current through the diode at reverse bias is zero. Since first diode is in forward bias and second diode is in reverse bias. So Only first diode will the current. Sanfoundry Global Education & Learning Series – Analog Circuits. To practice all areas of Analog Circuits, here is complete set of 1000+ Multiple Choice Questions and Answers.

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Analog Circuits Interview Questions and Answer...

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Analog Circuits Interview Questions and Answers for Freshers by Manish 5-7 minutes

This set of Analog Circuits Interview Questions and Answers for freshers focuses on “Ideal Diode Model – 2”. 1. Find the voltage across the resistor R if VA = -3V and VB = -5V. Use ideal diode model assumption.

a) 0V b) -3V c) -5V d) -4V View Answer Answer: a Explanation: In ideal diode model the diode is considered as a perfect conductor in forward bias and perfect insulator in reverse bias. That is voltage drop at forward bias is zero

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and current through the diode at reverse bias is zero. Since both diode is in reverse bias mode current through diode is zero. 2. Find current I if voltage V = 5V, VB = 2V, R1 & R2 = 2K. Use ideal diode model assumption.

a) 1.5mA b) 1.375mA c) 2mA d) 3mA View Answer Answer: d Explanation: In ideal diode model the diode is considered as a perfect conductor in forward bias and perfect insulator in reverse bias. That is voltage drop at forward bias is zero and current through the diode at reverse bias is zero. 4V forward biases the diode while 2V is reverse bias to the diode. So voltage across R1 is V-VB. That is 3V. Therefore, current through R1 = 3V/2k = 1.5mA. Current through R2 = 3/2K = 2.5mA. Therefore, total current I = 1.5+1.5 = 3mA. 3. Find current I if V = 5V and -5V when VB = 2V, R1 = 2K, 2 of 8

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R2 = 4K respectively are

a) 0A and 1.3mA b) 1.231mA and 0.33mA c) 3.25mA and 0A d) 1.58mA and 0A View Answer Answer: c Explanation: In ideal diode model the diode is considered as a perfect conductor in forward bias and perfect insulator in reverse bias. That is voltage drop at forward bias is zero and current through the diode at reverse bias is zero. V is forward biasing and VB is reverse biasing to diode. Current through resistor R1 = V/2k = 2.5mA. Current through resistor R2 = (V – VB ) /4k = 0.75mA. So total current is 3.25mA. At V = -5V, diode is reverse bias So the current is zero. 4. The output voltage V if Vin = 3V, R=5K, VB = 2V is

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a) 1V b) 4V c) 5V d) 2.5V View Answer Answer: a Explanation: In ideal diode model the diode is considered as a perfect conductor in forward bias and perfect insulator in reverse bias. That is voltage drop at forward bias is zero and current through the diode at reverse bias is zero. Vin reverse biases the diode and VB so total voltage is Vin – VB. 5. In the circuit below VB = 2V, Vin = 5V. The voltage V across resistor R is

a) 5V b) 2V c) 3V d) 7V View Answer Answer: b Explanation: In ideal diode model the diode is considered as a perfect conductor in forward bias and perfect insulator in reverse bias. That is voltage drop at forward bias is zero and current through the diode at reverse bias is zero. 4 of 8

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Since Vin reverse biases the diode it won’t be shown in resistor R. So only VB appears. 6. In the circuit Vin = 4V, VB = 3V, R = 5K. The voltage across diode V is

a) 1V b) 4V c) 3V d) 7V View Answer Answer: a Explanation: In ideal diode model the diode is considered as a perfect conductor in forward bias and perfect insulator in reverse bias. That is voltage drop at forward bias is zero and current through the diode at reverse bias is zero. Since Vin reverse biases the diode and VB forward biases the diode So total voltage across diode is Vin-VB. 7. In the circuit below Vin = 4V, R = 2K and VB = 2V. In these conditions the voltage across diode V is

a) -4V

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b) -2V c) 2V d) 0V View Answer Answer: d Explanation: In ideal diode model the diode is considered as a perfect conductor in forward bias and perfect insulator in reverse bias. That is voltage drop at forward bias is zero and current through the diode at reverse bias is zero. Since net voltage Vin – VB = 2V forward biases the diode voltage across diode is zero. 8. In the circuit shown in below I = 2mA, VB = 2V and R = 2K. The voltage V will be

a) 0V b) 2V c) 4V d) 1V View Answer Answer: b Explanation: In ideal diode model the diode is considered as a perfect conductor in forward bias and perfect insulator in reverse bias. That is voltage drop at forward bias is zero and current through the diode at reverse bias is zero. Since current I is forward bias to diode resistor R has no

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relevance so output voltage is VB. 9. In the circuit shown in below I = 2mA, VB = 2V and R = 2K. The voltage V will be

a) 2V b) 3V c) 6V d) 5V View Answer Answer: c Explanation: In ideal diode model the diode is considered as a perfect conductor in forward bias and perfect insulator in reverse bias. That is voltage drop at forward bias is zero and current through the diode at reverse bias is zero. Since diode is reverse biased by the current I, Voltage across R = 2mA x 2k = 4V. So total voltage will be 2+4=6V. 10. For circuit shown below Vin = 3V, R1 = 6K, R2 = 2K. The voltage V will be

a) 3V

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b) 0.75V c) 1V d) 1.134V View Answer Answer: a Explanation: In ideal diode model the diode is considered as a perfect conductor in forward bias and perfect insulator in reverse bias. That is voltage drop at forward bias is zero and current through the diode at reverse bias is zero. Since diode is forward biased entire voltage will appear across R2. Sanfoundry Global Education & Learning Series – Analog Circuits. To practice all areas of Analog Circuits for Interviews, here is complete set of 1000+ Multiple Choice Questions and Answers.

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Piecewise Linear Model of Diode Analog Circuits Questions and Answers by Manish 5-6 minutes

This set of Analog Circuits Multiple Choice Questions & Answers (MCQs) focuses on “Piecewise Linear Model of Diode-1”. 1. After cut-in voltage in piecewise linear model diode act as a a) Resistor b) Capacitor c) Conductor d) Insulator View Answer Answer: a Explanation: After cut –in voltage diode act as a resistor in piecewise linear mode. In normal operation diode current is exponentially related to voltage. 2. Reverse biased condition of a diode in piecewise linear model is equivalent to a) Resistor 1 of 8

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b) Capacitor c) Conductor d) Insulator View Answer Answer: d Explanation: For a diode in reverse bias mode current through the diode is in micro amperes or nano amperes. Hence we can assume it as zero. In piecewise linear model reverse current is assumed to zero. That is, as an insulator. 3. Voltage drop produced by a diode in piecewise linear mode is a) Constant and equal to knee voltage b) Varying linearly with voltage c) Varies exponentially with voltage d) Constant and equal to twice of knee voltage View Answer Answer: b Explanation: Voltage drop produced by diode in piecewise linear model is not constant. Since it contains effect of resistor, the diode voltage linearly increases as input voltage increases. 4. In the given circuit voltage V = 2V.cut-in voltage of diode is 0.7V. The current I through the circuit is (Assume piecewise linear model for diode)

a) 0.235mA 2 of 8

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b) 1.29mA c) 1.63mA d) 2.27mA View Answer Answer: d Explanation: Since diode is in forward bias mode it can replaced by the equivalent circuit

I = (V-VD)/R1+RD = (3-0.7)/1010 = 2.27mA. 5. In the given circuit input voltage Vin is 3V and V2 is 1V. The resistance R1 is 1.5K. Cut-in voltage of diode is 0.5V. Forward bias resistance is 10Ω. The Voltage V will be

a) 2.03mA b) 0.23mA c) 1.58mA d) 1.33mA View Answer Answer: d Explanation: Since both voltage sources are reverse bias to the diode, diode in the circuit disappears and equivalent circuit becomes as follows

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So current I = V1-V2/R = 3-1/1.5k = 1.33mA. 6. In the given circuit input voltage V1 is -3V and V2 is -1V. The resistance R1 is 1K. Cut-in voltage of diode is 0.5V. Forward bias resistance is 10Ω. The Voltage V will be (Use piecewise linear model of diode)

a) -1mA b) -2mA c) -0.2mA d) -0.1mA View Answer Answer: b Explanation: Since both voltage sources are in forward bias to diode, the equivalent circuit will be as follows

Since voltage across diode is 1V. current I = -3+1/1k = -2mA. 7. In the given circuit input voltage V is 2V and VB is 1V. The resistance R1 and R2 is 1K. Cut-in voltage of diode is 0.5V. Forward bias resistance is 10Ω. The current I will be

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(Use piecewise linear model of diode)

a) 0.29mA b) 0.21mA c) 0.36mA d) 0.15mA View Answer Answer: a Explanation: Since V-VB = 1V forward biases the diode, we can use equivalent circuit of diode as follows

Current through R1, I1 = 1V/R1 = 1mA. Current through R2, I2 = (1-VD )/(R2¬+RD) = (1-0.7)/1010 = 0.297mA. 8. In the given circuit input voltage V is 3V and VB is 1V. The resistance R1 and R2 is 1K. Cut-in voltage of diode is 0.5V. Forward bias resistance is 10Ω. The current I will be (Use piecewise linear model of diode)

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a) 0.96mA b) 2.13mA c) 1.56mA d) 1.23ma View Answer Answer: c Explanation: Since diode is in forward bias we can assume equivalent circuit model and assume following circuit

Let voltage across diode is V0 now voltage across branch is V-V0 Current I = (2-V0)/R1 +(2-V0VB)/R2 =(2-V0)/1000+((1-V0 ))/1000 …………………….(1) V0 = VD+ IRD = 0.7+10I Put this value in eq(1) That is, I = (2-0.7-10I)/1000+((1-0.7-10I))/1000 => 1000I = 1.6 – 20I => 1020 I = 1.6 That is, I = 1.6/1020 = 1.56mA. 9. In the given circuit input voltage V is -3V and VB is 1V. The resistance R1 and R2 is 1K. Cut-in voltage of diode is 0.5V. Forward bias resistance is 10Ω. The current I will be (Use piecewise linear model of diode)

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a) 1.2mA b) 0mA c) 0.8mA d) 1mA View Answer Answer: b Explanation: Since diode is in reverse bias mode there won’t be any current in the circuit. Both voltage sources reverse biases the diode. 10. In the given circuit input voltage Vin is 3V and VB is 1V. The resistance R is 1K. Cut-in voltage of diode is 0.5V. Forward bias resistance is 10Ω. The current I will be (Use piecewise linear model of diode)

a) 1V b) 3V c) 2.3V d) 1.3V

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View Answer Answer: b Explanation: Since Vin is reverse bias to the diode and greater than VB, the voltage Vin will appear on V. Hence V will be 3V. Sanfoundry Global Education & Learning Series – Analog Circuits. To practice all areas of Analog Circuits, here is complete set of 1000+ Multiple Choice Questions and Answers.

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Piecewise Linear Model of Diode Questions and Answers by Manish 5-6 minutes

This set of Analog Circuits Multiple Choice Questions & Answers (MCQs) focuses on “Piecewise Linear Model of Diode-2”. 1. In the given circuit input voltage Vin is 3V and VB is 1.5V. The resistance R is 1.5K. Cut-in voltage of diode is 0.5V. Forward bias resistance is 10Ω. The Voltage V will be

a) 2.7V b) 3V c) 0.8V d) 1.5V View Answer Answer: b Explanation: Since Vin is reverse bias to diode it will appear

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in output. Vin will appear across the diode and also VB is less than Vin so Vin will appear across output. 2. In the circuit shown below voltage Vin is 3V and VB is 2V. The resistor R is 1K. Cut-in voltage of diode is 0.7V. The voltage V is

a) 0.3V b) 1V c) 3V d) 0V View Answer Answer: d Explanation: The diode is reverse biased since voltage at p-side is less than voltage at n-side. Hence there is no current through the diode. Hence voltage across resistor is zero. 3. In the circuit shown below voltage Vin is -3V and VB is -2V. The resistor R is 1K. Cut-in voltage of diode is 0.7V. Forward bias resistance is 10Ω. The voltage V is

a) -0.23V

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b) 0.29V c) -2.72V d) -1.3V View Answer Answer: b Explanation: Effective voltage across diode is one volt. Hence diode is in forward bias mode. So we can apply equivalent circuit of diode. Net voltage through R and RD is -3—2+0.7 = -0.3V Current through the circuit is 0.3/(R+RD) = 0.3/(1010) = 0.29mA. Hence voltage across R is 1Kx0.29mA = 0.29V.

4. In the circuit shown below current I is 2mA and VB is 1V. The resistor R is 1K. Cut-in voltage of diode is 0.7V. Forward bias resistance is 10Ω. The voltage V is

a) 3V b) 2V c) 1V d) 0.3V View Answer Answer: a Explanation: Since current source is reverse bias to the diode current es through resistor R. Voltage across 3 of 9

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resistor R is 2mA x 1k =2V. Since resistor and diodes are parallel net output voltage V is VB + voltage across resistor R = 1+2 = 3V. 5. In the circuit shown below current I is 2mA and VB is -1V. The resistor R is 1K. Cut-in voltage of diode is 0.7V. Forward bias resistance is 10Ω. The voltage V is

a) 1.3V b) 0.3V c) 1V d) 2V View Answer Answer: c Explanation: Since current source is reverse bias to the diode current es through resistor R. Voltage across resistor R is 2mA x 1k =2V. Since resistor and diodes are parallel net output voltage V is VB + voltage across resistor R = -1+2 = 1V. 6. In the circuit shown below voltage Vin is 3V and VB is 1V. The resistor R1 and R2 are 1K. Assume both diodes are identical. Forward bias resistance is 10Ω. Cut-in voltage of diode is 0.7V. The voltage Vout is

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a) 1.235V b) 0.234V c) 1.314V d) 1.564V View Answer Answer: c Explanation: Since D1 and D2 are forward biased we can replace them with their equivalent diagram.

Assume I be the current through the circuit. By kirchoff’s voltage rule, Vout = -VD+IRD+IR2 ————(1) Current through R1 (Vin-Vout)/1k = (3-Vout)/1k Current through diode is (Vin-Vout-VD-VB)/RD = (0.3-Vout)/10 Total current I = (3-Vout)/1000+(1.3-Vout)/10 = 1.330-1.010Vout Substitute this in eq(1) That is, Vout = -0.7 + 1010(1.33-1.01Vout) 1021Vout = 1342. Therefore, Vout = 1.314V. 7. In the circuit shown below voltage Vin is -3V and VB is -1V. The resistor R1 and R2 are 1K. Assume both diodes are identical. Forward bias resistance is 10Ω .Cut-in voltage of diode is 0.7V. The voltage Vout is

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a) -2V b) -3V c) -1V d) -.0.7V View Answer Answer: b Explanation: Since both diodes are in reverse bias mode applied voltage Vin will appear on Vout. Diode D1 and D2 disappears and leaves the terminal as open. 8. In the circuit shown below voltage Vin is 3V and VB is 1V. The resistor R1 and R2 are 1K. Assume both diodes are identical. Forward bias resistance is 10Ω. Cut-in voltage of diode is 0.7V. The voltage Vout is

a) 1.14V b) 1.23V c) 0.32V d) 1.34V View Answer

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Answer: a Explanation:

Assume I be the current through the circuit. By kirchoff’s voltage rule, Vout = IR2 ————(1) Current through R1 (Vin-Vout-VD)/1.01k = (2.3Vout)/1010 Current through diode D2 is 0 since D2 is in reverse bias mode. current I = (2.3-Vout)/1010 Substitute this in eq(1) That is, Vout =(2.3-Vout)/1010 x 1000 => 1.99Vout = 2.27 => Vout = 2.27/1.99 =1.144V. 9. In the circuit shown below voltage Vin is 3V and VB1 is -1V and VB2 is 1V. Assume both diodes are identical. Cut-in voltage of diode is 0.7V. Forward bias resistance is 10Ω. The voltage Vout is

a) 0.6V b) 1V c) 1.7V d) 2V View Answer Answer: a Explanation: In this condition both diodes are forward biased

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This circuit can be further reduced to by assuming VB as 1V

By network analysis using kirchoff’s voltage rule current through RD2 will be 0.09A. The voltage in Vout will be VB+VD-0.09×10 = 0.6V. 10. In the circuit shown below, cut-in voltage of diode is 0.7V. Forward bias resistance is 10Ω. The voltage V is

a) 0.69V b) 0.7V c) 0.68V d) 0.72V View Answer Answer: d Explanation: Since diode is in forward bias we can replace diode with voltage source of 0.7V and resistor of resistance 10Ω.

Vout will be IRD+VD = 2mAx10 + 0.7 = 0.72V. Sanfoundry Global Education & Learning Series –

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Analog Circuits. To practice all areas of Analog Circuits, here is complete set of 1000+ Multiple Choice Questions and Answers.

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Constant Voltage Drop Model Analog Circuits Questions and Answers by Manish 5-7 minutes

This set of Analog Circuits Multiple Choice Questions & Answers (MCQs) focuses on “Constant Voltage Drop Model-1”. 1. In constant voltage drop model diode in forward bias is considered as a a) Resistor b) Perfect conductor c) Perfect insulator d) capacitor View Answer Answer: b Explanation: In constant voltage drop model the diode is considered as a perfect conductor in forward bias and perfect insulator in reverse bias. That is voltage drop at forward bias is zero and current through the diode at reverse bias is zero. In this model at forward bias diode can be replaced as a cell and in reverse bias diode can be

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avoided by considering the terminals are open. 2. In constant voltage drop diode in reverse bias is considered as a a) Resistor b) Perfect conductor c) Perfect insulator d) capacitor View Answer Answer: c Explanation: In constant voltage drop the diode is considered as a perfect conductor in forward bias and perfect insulator in reverse bias. That is voltage drop at forward bias is zero and current through the diode at reverse bias is zero. In this model at forward bias diode can be replaced as a cell and in reverse bias diode can be avoided by considering the terminals are open. 3. The current I through the circuit if we consider diode in constant voltage drop model is (Take VD as 0.5V)

a) 2mA b) 2.5mA c) 3.5mA d) 1mA View Answer

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Answer: b Explanation: In constant voltage drop model at forward bias diode can be replaced as a cell and in reverse bias diode can be avoided by considering the terminals are open. Since D1 is in forward biased there will be a voltage drop of 0.5V. So net voltage will be 2.5V and hence current is 2.5mA. 4. The voltage across the diode Vout if Vin is -5V and resistance is 10K is (Use constant voltage drop model of diode and take VD as 0.5V)

a) -3V b) 0V c) -5V d) -2.5V View Answer Answer: c Explanation: In constant voltage drop model at forward bias diode can be replaced as a cell and in reverse bias diode can be avoided by considering the terminals are open. Since diode is reverse biased entire voltage will appear across diode. 5. The voltage across the diode Vout if Vin is 5V and resistance is 10K is (Use constant voltage drop model of diode and take VD as 3 of 8

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Constant Voltage Drop Model - Analog Circuits...

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0.5V)

a) 5V b) 0.5V c) 2.5V d) 0V View Answer Answer: b Explanation: In constant voltage drop model at forward bias diode can be replaced as a cell and in reverse bias diode can be avoided by considering the terminals are open. Since diode is forward biased and potential is greater than VD voltage across diode is VD. 6. The current I through the circuit I if voltage v is -3V is (Use constant voltage drop model of diode and take VD as 0.5V)

a) 10mA b) 1mA c) 3mA d) 0mA View Answer Answer: d

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Constant Voltage Drop Model - Analog Circuits...

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Explanation: In constant voltage drop model at forward bias diode can be replaced as a cell and in reverse bias diode can be avoided by considering the terminals are open. Since diode is reverse biased there is no current through the circuit. 7. If current source produces a current of 1mA and resistance R is 3K then voltage across the resistor is (Use constant voltage drop model of diode and take VD as 0.5V)

a) 3V b) 0V c) 0.5V d) 0.3V View Answer Answer: c Explanation: In constant voltage drop model at forward bias diode can be replaced as a cell and in reverse bias diode can be avoided by considering the terminals are open. Since diode is forward biased and maximum voltage if all current through resistor Is 3V which is greater than VD voltage across diode is VD. 8. If resistance R1 is 10K, V2 = 2V, V1 = 3V then the current I through the circuit will be (Use constant voltage drop model of diode and take VD as 0.5V)

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Constant Voltage Drop Model - Analog Circuits...

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a) 0.3mA b) 0.6mA c) 0.7mA d) 0.1mA View Answer Answer: d Explanation: In ideal diode model the diode is considered as a perfect conductor in forward bias and perfect insulator in reverse bias. That is voltage drop at forward bias is zero and current through the diode at reverse bias is zero. Since both voltage is reverse bias to diode the diode will disappear from the circuit. Then effective voltage becomes 3-2 = 1V so current is 1/10K = 0.1mA. 9. If resistance R1 is 10K, V2 = -2V, V1 = -3V then the current I through the circuit will be (Use constant voltage drop model of diode and take VD as 0.5V)

a) 0.5mA b) 0.25mA c) 2mA

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Constant Voltage Drop Model - Analog Circuits...

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d) 3mA View Answer Answer: b Explanation: In constant voltage drop model at forward bias diode can be replaced as a cell and in reverse bias diode can be avoided by considering the terminals are open. Since both voltage sources are forward biased the diode V2 and diode can be replaced by a single cell of VD. So net voltage in the circuit is 2.5V. So the current will be 0.25mA. 10. What will be the voltage Vout if VA = 3V and VB = -5V? (Use constant voltage drop model of diode and take VD as 0.5V)

a) 2.5 b) 3.5 c) -5.5 d) -4.5 View Answer Answer: a Explanation: In constant voltage drop model at forward bias diode can be replaced as a cell and in reverse bias diode can be avoided by considering the terminals are open. Since first diode is forward biased and second diode reverse bias, first voltage appears on resistor with a voltage drop of VD.

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Constant Voltage Drop Model - Analog Circuits...

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Sanfoundry Global Education & Learning Series – Analog Circuits. To practice all areas of Analog Circuits, here is complete set of 1000+ Multiple Choice Questions and Answers.

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Analog Circuits Questions and Answers for Expe...

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Analog Circuits Questions and Answers for Experienced by Manish 5-7 minutes

This set of Analog Circuits Questions and Answers for Experienced people focuses on “Constant Voltage Drop Model-2”. 1. Voltage across the resistor R if VA = -3V and VB = -5V is (Use constant voltage drop model assumption and take VD = 0.5V)

a) 0V b) -3V c) -5V d) -4V View Answer Answer: a Explanation: In constant voltage drop model at forward bias diode can be replaced as a cell and in reverse bias diode can be avoided by considering the terminals are open. 1 of 9

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2. Current I if voltage V = 5V, VB = 2V, R1 & R2 = 2K (Use constant voltage drop model assumption and take VD = 0.5V)

a) 1.25mA b) 1mA c) 2.75mA d) 1.75mA View Answer Answer: c Explanation: In constant voltage drop model at forward bias diode can be replaced as a cell and in reverse bias diode can be avoided by considering the terminals are open. Since Vin and VB are opposite net voltage is 3V. Voltage at R1 is 3V so current is 1.5mA. Voltage at R2 is 3-0.5 = 2.5V. So the current is 1.25mA. The net current is 2.75mA. 3. Current I if V = 5V and -5V when VB = 2V, R1 = 2K, R2 = 4K respectively are (Use constant voltage drop model assumption and take VD = 0.5V)

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Analog Circuits Questions and Answers for Expe...

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a) 1.3mA, 0.23mA b) 2.875mA, 0mA c) 2mA, 0mA d) 1.423mA, 0 mA View Answer Answer: b Explanation: In constant voltage drop model at forward bias diode can be replaced as a cell and in reverse bias diode can be avoided by considering the terminals are open. Since diode is in forward bias net total voltage becomes 4.5V. Current through branch 1 will be 4.5V / 2K = 2.25mA. Current through branch 2 will be (4.5-2)/4K = 0.625mA. So net current is sum of these two. Therefore, net current is 2.875mA. 4. The output voltage V if Vin = 3V, R=5K, VB = 2V is (Use constant voltage drop model assumption and take VD = 0.5V)

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Analog Circuits Questions and Answers for Expe...

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a) 0V b) 3.5V c) 2.5V d) 1.5V View Answer Answer: d Explanation: In constant voltage drop model at forward bias diode can be replaced as a cell and in reverse bias diode can be avoided by considering the terminals are open. Since Vin is reverse bias to the diode all Vin will appear across diode. Since Vin is opposite to VB net voltage will be Vin-(VB-VD). 5. In the circuit below VB = 2V, Vin = 5V. The voltage V across resistor R is (Use constant voltage drop model assumption and take VD = 0.5V)

a) 1.5V b) 2.5V c) 3.5V

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Analog Circuits Questions and Answers for Expe...

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d) 2V View Answer Answer: a Explanation: In constant voltage drop model at forward bias diode can be replaced as a cell and in reverse bias diode can be avoided by considering the terminals are open. Since Vin reverse bias to the diode it has no effect in R. Therefore, VB alone control voltage at R. So voltage across R will be same as VB with a voltage drop of VD. 6. In the circuit Vin = 4V, VB = 3V, R = 5K. The voltage across diode V is (Use constant voltage drop model assumption and take VD = 0.5V)

a) 0V b) 0.5V c) 1V d) 1.5V View Answer Answer: c Explanation: In constant voltage drop model at forward bias diode can be replaced as a cell and in reverse bias diode can be avoided by considering the terminals are open. Since diode is in reverse bias mode, the net voltage will appear on the voltage that is 1V. 5 of 9

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7. In the circuit below Vin = 4V, R = 2K and VB = 2V. In these conditions the voltage across diode V is (Use constant voltage drop model assumption and take VD = 0.5V)

a) 2.5 b) 4.5 c) 0.5 d) 1.5 View Answer Answer: c Explanation: In constant voltage drop model at forward bias diode can be replaced as a cell and in reverse bias diode can be avoided by considering the terminals are open. Since diode is forward biased it will produce a voltage drop of VD. 8. In the circuit shown in below I = 2mA, VB = 2V and R = 2K. The voltage V will be (Use constant voltage drop model assumption and take VD = 0.5V)

a) 0V 6 of 9

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b) 2.5V c) 6V d) 3.5V View Answer Answer: b Explanation: In constant voltage drop model at forward bias diode can be replaced as a cell and in reverse bias diode can be avoided by considering the terminals are open. Since current source forward bases the diode voltage drop across diode is VD. So net voltage output is VD+VB. 9. In the circuit shown in below I = 2mA, VB = 2V and R = 2K. The voltage V will be (Use constant voltage drop model assumption and take VD = 0.5V)

a) 4V b) 3V c) 6V d) 5.5V View Answer Answer: c Explanation: In constant voltage drop model at forward bias diode can be replaced as a cell and in reverse bias diode can be avoided by considering the terminals are open. Since current source reverse biases diode, all current

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Analog Circuits Questions and Answers for Expe...

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through resistor R. So voltage across resistor is 4V. Since voltage source cannot produce current due to lack of closed circuit total voltage at the output is 6V. 10. For circuit shown below Vin = 3V, R1 = 6K, R2 = 2K. The voltage V will be (Use constant voltage drop model assumption and take VD = 0.5V)

a) 2V b) 3V c) 3.5V d) 2.5V View Answer Answer: d Explanation: In constant voltage drop model at forward bias diode can be replaced as a cell and in reverse bias diode can be avoided by considering the terminals are open. Since diode is forward biased and parallel to resistor R1 voltage drop across diode is VD. So net voltage equals to Vin –VD. Sanfoundry Global Education & Learning Series – Analog Circuits. To practice all areas of Analog Circuits for Experienced people, here is complete set of 1000+ Multiple Choice

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Questions and Answers.

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Transition Capacitance - Analog Circuits Questi...

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Transition Capacitance - Analog Circuits Questions and Answers by Manish 6-7 minutes

This set of Analog Circuits Multiple Choice Questions & Answers (MCQs) focuses on “Transition Capacitance”. 1. Which of the following is not known as transition capacitance a) Junction capacitance b) Space-Charge capacitance c) Diffusion capacitance d) Barrier capacitance View Answer Answer: c Explanation: Transition capacitance is the capacitance exhibited by a diode due to the p-side and n-side of the diode is separated by a distance of depletion width same as in an electrolytic capacitor. The other names for this is Junction capacitance, Space-Charge capacitance, Barrier capacitance, Depletion region capacitance. 2. Which of the following is not known as transition capacitance

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Transition Capacitance - Analog Circuits Questi...

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a) Depletion region capacitance b) Space-Charge capacitance c) Nominal capacitance d) Junction capacitance View Answer Answer: c Explanation: Transition capacitance is the capacitance exhibited by a diode due to the p-side and n-side of the diode is separated by a distance of depletion width same as in an electrolytic capacitor. The other names for this is Junction capacitance, Space-Charge capacitance, Barrier capacitance, Depletion region capacitance. 3. Transition capacitance of a diode is directly proportional to a) Area of cross section b) Width of depletion region c) Reverse voltage applied across the terminals d) Drift current View Answer Answer: a Explanation: Transition capacitance is the capacitance exhibited by a diode due to the p-side and n-side of the diode is separated by a distance of depletion width same as in an electrolytic capacitor. The equation of transition capacitance = ƸA/W Where Ƹ = permittivity of the material of diode , W = depletion width A = area of cross section.

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Transition Capacitance - Analog Circuits Questi...

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4. Transition capacitance of a diode is inversely proportional to a) Area of cross section b) Width of depletion region c) Relative permittivity d) Drift current View Answer Answer: b Explanation: Transition capacitance is the capacitance exhibited by a diode due to the p-side and n-side of the diode is separated by a distance of depletion width same as in an electrolytic capacitor. The equation of transition capacitance = ƸA/W Where Ƹ = permittivity of the material of diode , W = depletion width A = area of cross section. 5. As reverse bias voltage increases transition capacitance a) Increases b) Decreases c) Doesn’t depend upon voltage d) constant View Answer Answer: b Explanation: Transition capacitance is the capacitance exhibited by a diode due to the p-side and n-side of the diode is separated by a distance of depletion width same as in an electrolytic capacitor. The equation of transition capacitance = ƸA/W

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Transition Capacitance - Analog Circuits Questi...

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Where Ƹ = permittivity of the material of diode , W = depletion width A = area of cross section As reverse bias increases depletion width also increases hence transition capacitance decreases. 6. Relation between relative permittivity and transition capacitance is, they are a) Inversely proportional b) Directly proportional c) Independent d) Directly proportional with degree 2. View Answer Answer: b Explanation: Transition capacitance is the capacitance exhibited by a diode due to the p-side and n-side of the diode is separated by a distance of depletion width same as in an electrolytic capacitor. The equation of transition capacitance = ƸA/W Where Ƹ = permittivity of the material of diode , W = depletion width A = area of cross section Relative permittivity is directly proportional to permittivity of material. 7. For a diode the transition capacitance was 10pF. The depletion width changed from 1µm to 10 µm. All other conditions remain unchanged. The new diode capacitance is a) 5pF

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Transition Capacitance - Analog Circuits Questi...

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b) 1.414pF c) 1pF d) 10pF View Answer Answer: c Explanation: The equation of transition capacitance = ƸA/W Where Ƹ = permittivity of the material of diode , W = depletion width A = area of cross section Since depletion width increased 10 times and all other quantities are same, the capacitance decrease by 10 times. 8. For a diode the transition capacitance was 15pF. The diode is replaced with another diode of same material with twice cross sectional area. Terminal voltage remains unchanged. The capacitance of new diode is a) 15pF b) 30pF c) 60pF d) 7.5pF View Answer Answer: b Explanation: The equation of transition capacitance = ƸA/W Where Ƹ = permittivity of the material of diode , W = depletion width A = area of cross section Since A becomes 2A capacitance also doubles. 9. A diode is replaced with another diode of different material. The ratio of relative permittivity of new material to 5 of 7

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Transition Capacitance - Analog Circuits Questi...

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old is 0.5. The initial capacitance was 20pF, then final capacitance will be a) 15pF b) 20pF c) 10pF d) 2pF View Answer Answer: c Explanation: The equation of transition capacitance = ƸA/W Where Ƹ = permittivity of the material of diode , W = depletion width A = area of cross section Since permittivity becomes half capacitance also halves. 10. A diode had a transition capacitance of 1pF and depletion width of 1 µm. The capacitance changes to 10 pF when the depletion width changes. The final depletion width is a) 10 µm b) 0.1 µm c) 1 µm d) 100 µm View Answer Answer: b Explanation: The equation of transition capacitance = ƸA/W Where Ƹ = permittivity of the material of diode , W = depletion width A = area of cross section Since depletion with and capacitance are inversely

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Transition Capacitance - Analog Circuits Questi...

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proportional Depletion width decreases to 0.1 µm. Sanfoundry Global Education & Learning Series – Analog Circuits. To practice all areas of Analog Circuits, here is complete set of 1000+ Multiple Choice Questions and Answers.

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Load Line Analysis - Analog Circuits Questions ...

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Load Line Analysis - Analog Circuits Questions and Answers by Manish 5-6 minutes

This set of Analog Circuits Multiple Choice Questions & Answers (MCQs) focuses on “Load Line Analysis”. 1. From the circuit and the diode characteristics given alongside, and assuming R=2k, what is the value of diode voltage at the operating point?

a) 0.78 V b) 10 V c) 0 V 1 of 8

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Load Line Analysis - Analog Circuits Questions ...

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d) None of the mentioned View Answer Answer: a Explanation: On drawing the load line with the equation: VD = ED + IDRD, we get the operating point with the value of at voltage at around 0.7-0.8 V. Hence, VDq=0.78 V. 2. From the circuit and the diode characteristics given and assuming R=1k, what is the value of diode current at operating point?

a) 20 mA b) 9.3 mA c) 0 mA d) None of the mentioned View Answer Answer: b Explanation: On drawing the load line with the equation: VD = ED + IDRD, we get the operating point with the value of 2 of 8

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Load Line Analysis - Analog Circuits Questions ...

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current at around 9.2-9.4 mA. Hence, IDq=9.3 mA 3. From the circuit and the diode characteristics given and assuming R=1k, what is the value of voltage across the resistor at operating point?

a) 10 V b) 0 V c) 9.3 V d) None of the mentioned View Answer Answer: c Explanation: We know that VR=IDR = 9.3 x 1 = 9.3 V. 4. From the given load line characteristics, what is the relation between R1 and R2 , assuming constant source EMF?

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Load Line Analysis - Analog Circuits Questions ...

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a) R1 > R2 b) R1 = R2 c) R1 < R2 d) Can’t be determined View Answer Answer: c Explanation: Here, the y-intercept=E/R hence, lower the y-intercept, higher the value of R, Hence, R1
a) 0 V b) 9.25 V c) 10 V d) None of the mentioned View Answer Answer: a

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Load Line Analysis - Analog Circuits Questions ...

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Explanation: The value of voltage calculated across resistor is calculated by E-VD, which is constant for both cases. 6. From the given load characteristics, what is the value of diode current at operating point for the characteristics of R2?

a) 9.3 mA b) 4.6 mA c) 0 mA d) None of the mentioned View Answer Answer: b Explanation: At the point of intersection, the value of current is around 4.6 mA. 7. From the given load characteristics, what is the value of diode voltage at operating point for the characteristics of R2?

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Load Line Analysis - Analog Circuits Questions ...

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a) 0 V b) 10 V c) 0.7 V d) None of the mentioned View Answer Answer: c Explanation: At the point of intersection, the value of diode voltage is approximately 0.7 V. 8. Using the approximate equivalent model of a silicon diode and taking E=10 V and R=1k, what is the value of diode voltage at operating point? a) 0.7 V b) 0.3 V c) 10 V d) None of the mentioned View Answer Answer: a Explanation: In the approximate equivalent model, the diode voltage is fixed at the forward bias threshold voltage, which for a silicon diode is equal to 0.7 V 9. Using the approximate equivalent model of a silicon diode and taking E=10 V and R=1k, what is the value of diode voltage at operating point? a) 9.25 mA b) 10 mA c) 0 mA d) None of the mentioned View Answer 6 of 8

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Load Line Analysis - Analog Circuits Questions ...

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Answer: a Explanation: In the approximate equivalent model, the characteristic is assumed to be a vertical upward line at V=0.7 V. Hence, the current at point of intersection is determined to be 9.25 mA 10. Using the ideal diode model of a silicon diode and taking E=10 V and R=1k, what is the value of diode voltage at operating point? a) 0.7 V b) 0 V c) 10 V d) None of the mentioned View Answer Answer: b Explanation: In ideal diode model, we take the forward threshold voltage to be zero. Hence thee diode characteristic is represented as the upper half of the y-axis. Hence, VD = 0 V. 11. Using the ideal diode model of a silicon diode and taking E=10 V and R=1k, what is the value of diode current at operating point? a) 9.25 mA b) 10 mA c) 0 mA d) None of the mentioned View Answer Answer: b Explanation: In ideal diode model, we take the forward 7 of 8

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Load Line Analysis - Analog Circuits Questions ...

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threshold voltage to be zero. Hence thee diode characteristic is represented as the upper half of the y-axis. Hence, ID= E/R = 10 mA. 12. The ideal diode model of a silicon semiconductor diode gives an error that is greater than that obtained in approximate equivalent model. Is the statement true or false? a) True b) False View Answer Answer: a Explanation: In the ideal diode we assume the diode voltage as zero whereas in the approximate equivalent circuit model, we assume VD = 0.7 V and the actual value is somewhere about 0.75-0.8 V. Hence, approximate equivalent model is more accurate. Sanfoundry Global Education & Learning Series – Analog Circuits. To practice all areas of Analog Circuits, here is complete set of 1000+ Multiple Choice Questions and Answers.

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Halfwave Rectifier - Analog Circuits Questions a...

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Halfwave Rectifier - Analog Circuits Questions and Answers by Manish 4-5 minutes

This set of Analog Circuits Multiple Choice Questions & Answers (MCQs) focuses on “Halfwave Rectifier”. 1. DC average current of a half wave rectifier output is (Where Im is the maxImum peak current of input a) 2Im/ᴨ b) Im/ᴨ c) Im/2ᴨ d) 1.414Im/ᴨ View Answer Answer: b Explanation: Average DC current of half wave rectifier is Im/ᴨ . Since output of half wave rectifier contains only one half of the input. The average value is the half of the area of one half cycle of sine wave with peak Im. This is equal to Im/ᴨ. 2. DC power output of half wave rectifier is equal to (Im is the peak current and RL is the load resistance) a) (2Im2/ ᴨ2)RL

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b) (Im2/2 ᴨ2)RL c) (Im2/ ᴨ2)RL

d) (4Im2/ ᴨ2)RL View Answer Answer: c Explanation: Average DC power of half wave rectifier output is (Im2/ ᴨ2)RL. Since power is VDC * IDC, = Im/ᴨ x Vm/ᴨ = VmIm/ ᴨ2

We know Vm = Im RL. Therefore, power = (Im2/ ᴨ2)RL. 3. Ripple factor of half wave rectifier is a) 1.414 b) 1.21 c) 1.3 d) 0.48 View Answer Answer: b Explanation: Ripple factor of a rectifier is the measure of effectiveness of a power supply filter in reducing the ripple voltage. It is calculated by taking ratio of ripple voltage to DC output voltage. For a half wave rectifier, it is 1.21. 4. If input frequency is 50Hz then ripple frequency of half wave rectifier will be equal to a) 100Hz b) 50Hz c) 25Hz d) 500Hz View Answer 2 of 5

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Halfwave Rectifier - Analog Circuits Questions a...

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Answer: b Explanation: The ripple frequency of output and input is same since one half cycle of input is ed and other half cycle is blocked. So effectively frequency is the same. 5. Transformer utilization factor of a half wave rectifier is equal to a) 0.267 b) 0.287 c) 0.297 d) 0.256 View Answer Answer: b Explanation: Transformer utilization factor is the ratio of AC power delivered to load to the DC power rating. This factor indicates effectiveness of transformer usage by rectifier. For half wave rectifier it is low and equal to 0.287. 6. If peak voltage on a half wave rectifier circuit is 5V and diode cut-in voltage is 0.7, then peak inverse voltage on diode will be a) 5.7V b) 3.6V c) 4.3V d) 5V View Answer Answer: c Explanation: PIV is the maxImum reveres bias voltage that can be appeared across a diode in the circuit. If PIV rating of the diode is less than this value breakdown of diode may 3 of 5

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Halfwave Rectifier - Analog Circuits Questions a...

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occur. For a half wave rectifier PIV of diode is Vm – VD. Therefore, PIV is 5-0.7V. 7. Efficiency of half wave rectifier is a) 50% b) 81.2% c) 40.6% d) 45.3% View Answer Answer: c Explanation: Efficiency of a rectifier is the effectiveness of rectifier to convert AC to DC. For half wave rectifier it is only 40.6%. 8. In an half wave rectifier, the input sine wave is 200sin100 ᴨt. The average output voltage is a) 57.456V b) 60.548V c) 75.235V d) 63.694V View Answer Answer: d Explanation: The equation of sine wave is in the form Em sin wt. Therefore, Em=200 Hence output voltage is Em/ ᴨ. That is 200/ ᴨ. 9. In an half wave rectifier, the input sine wave is 200sin200 ᴨt. If load resistance is of 1k then average DC power output of half wave rectifier is a) 3.25W 4 of 5

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Halfwave Rectifier - Analog Circuits Questions a...

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b) 4.05W c) 5.02W d) 6.25W View Answer Answer: b Explanation: The equation of sine wave is in the form Em sin wt. On comparing Em = 200

Power = Em2/ ᴨ2RL = 200/ ᴨ2x 1000. 10. In an half wave rectifier, the input sine wave is 250sin100 ᴨt. The output ripple frequency of rectifier will be a) 100Hz b) 200Hz c) 50Hz d) 25Hz View Answer Answer: c Explanation: The equation of sine wave is in the form Em sin wt. On comparing equation w = 100 ᴨ rad/s We know w=2 ᴨ x frequency. Therefore, frequency = 50 Hz. Ripple frequency and input frequency are the same. Sanfoundry Global Education & Learning Series – Analog Circuits. To practice all areas of Analog Circuits, here is complete set of 1000+ Multiple Choice Questions and Answers.

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Fullwave Rectifier - Analog Circuits Questions a...

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Fullwave Rectifier - Analog Circuits Questions and Answers by Manish 4-5 minutes

This set of Analog Circuits Multiple Choice Questions & Answers (MCQs) focuses on “Fullwave Rectifier”. 1. DC average current of a center taped full wave rectifier (Where Im is the maxImum peak current of input) a) 2Im/ᴨ b) Im/ᴨ c) Im/2ᴨ d) 1.414Im/ᴨ View Answer Answer: a Explanation: Average DC current is the average current in the output of rectifier. For a center taped full wave rectifier, if a sinusoidal input is given output will contain only one half cycle repeatedly. So average current will be twice as half wave rectifier. 2. DC power output of center taped full wave rectifier is equal to (Im is the peak current and RL is the load resistance)

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Fullwave Rectifier - Analog Circuits Questions a...

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a) (2Im2/ ᴨ2)RL b) (Im2/2 ᴨ2)RL c) (Im2/ ᴨ2)RL

d) (4Im2/ ᴨ2)RL View Answer Answer: d Explanation: DC output power is the power output of the rectifier. It is equal to VDCIDC. We know VDC for a center taped rectifier is 2Vm/ᴨ and IDC for a center tap rectifier is 2Im/ᴨ. We also know VDC = IDC/RL.

Hence output power is (4Im2/ ᴨ2)RL. 3. Ripple factor of center taped full wave rectifier is a) 1.414 b) 1.21 c) 1.3 d) 0.48 View Answer Answer: d Explanation: Ripple factor of a rectifier is the measure of effectiveness of a power supply filter in reducing the ripple voltage. It is calculated by taking ratio of ripple voltage to DC output voltage. For a center taped full wave rectifier, it is 0.482. 4. If input frequency is 50Hz then ripple frequency of center taped full wave rectifier will be equal to a) 100Hz b) 50Hz 2 of 6

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c) 25Hz d) 500Hz View Answer Answer: a Explanation: Since in the output of center taped rectifier one half cycle is repeated hence frequency will twice as that of input frequency. That is 100Hz. 5. Transformer utilization factor of a center taped full wave rectifier is equal to a) 0.623 b) 0.678 c) 0.693 d) 0.625 View Answer Answer: c Explanation: Transformer utilization factor is the ratio of AC power delivered to load to the DC power rating. This factor indicates effectiveness of transformer usage by rectifier. For center taped full wave rectifier it is equal to 0.693. 6. If peak voltage on a center taped full wave rectifier circuit is 5V and diode cut-in voltage is 0.7, then peak inverse voltage on diode will be a) 4.3V b) 9.3V c) 5.7V d) 10.7V View Answer Answer: b 3 of 6

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Explanation: PIV is the maxImum reveres bias voltage that can be appeared across a diode in the circuit. If PIV rating of the diode is less than this value breakdown of diode may occur. For a center tap full wave rectifier PIV of diode is 2Vm – VD. Therefore, PIV is 10-0.7V. 7. Efficiency of center taped full wave rectifier is a) 50% b) 81.2% c) 40.6% d) 45.3% View Answer Answer: b Explanation: Efficiency of a rectifier is the effectiveness of rectifier to convert AC to DC.It is obtained by taking ratio of DC power output to maxImum AC power delivered to load. It is usually expressed in percentage. For center taped full wave rectifier, it is 81.2%. 8. In an center taped full wave rectifier, the input sine wave is 20sin500 ᴨt. The average output voltage is a) 12.73V b) 6.93V c) 11.62V d) 3.23V View Answer Answer: a Explanation: The equation of sine wave is in the form Em sin wt. Therefore, Em=20 4 of 6

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Fullwave Rectifier - Analog Circuits Questions a...

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Hence output voltage is 2Em/ ᴨ. That is 40/ ᴨ. 9. In an center taped full wave rectifier, the input sine wave is 200sin50 ᴨt. If load resistance is of 1k then average DC power output of half wave rectifier is a) 12.56W b) 16.20W c) 4.02W d) 8.04W View Answer Answer: b Explanation: The equation of sine wave is in the form Em sin wt. On comparing Em = 200

Power = 4Em2/ ᴨ2RL = 800/ ᴨ2x 1000 = 16.20W. 10. In an center taped full wave rectifier, the input sine wave is 250sin100 ᴨt. The output ripple frequency of rectifier will be a) 50Hz b) 200Hz c) 100Hz d) 25Hz View Answer Answer: c Explanation: The equation of sine wave is in the form Em sin wt. Therefore, w = 100ᴨ that is, frequency f = w/2ᴨ = 50Hz Since output of center taped full wave rectifier have double the frequency of input, output frequency is 100Hz. 5 of 6

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Fullwave Rectifier - Analog Circuits Questions a...

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Sanfoundry Global Education & Learning Series – Analog Circuits. To practice all areas of Analog Circuits, here is complete set of 1000+ Multiple Choice Questions and Answers.

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Bridge Rectifier - Analog Circuits Questions and...

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Bridge Rectifier - Analog Circuits Questions and Answers by Manish 4-5 minutes

This set of Analog Circuits Multiple Choice Questions & Answers (MCQs) focuses on “Bridge Rectifier”. 1. DC average current of a bridge full wave rectifier (Where Im is the maxImum peak current of input) a) 2Im/ᴨ b) Im/ᴨ c) Im/2ᴨ d) 1.414Im/ᴨ View Answer Answer: a Explanation: Average DC current is the average current in the output of rectifier. For a bridge full wave rectifier, if a sinusoidal input is given output will contain only one half cycle repeatedly. So average current will be twice as half wave rectifier. 2. DC power output of bridge full wave rectifier is equal to (Im is the peak current and RL is the load resistance) a) (2Im2/ ᴨ2)RL

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Bridge Rectifier - Analog Circuits Questions and...

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b) (4Im2/ ᴨ2)RL c) (Im2/ ᴨ2)RL

d) (Im2/2 ᴨ2)RL View Answer Answer: b Explanation: DC output power is the power output of the rectifier. It is equal to VDCIDC. We know VDc for a bridge rectifier is 2Vm/ᴨ and IDC for a bridge rectifier is 2Im/ᴨ. We also know VDC = IDC/RL. Hence output power is (4Im2/ ᴨ2)RL

3. Ripple factor of bridge full wave rectifier is a) 1.414 b) 1.212 c) 0.482 d) 1.321 View Answer Answer: c Explanation: Ripple factor of a rectifier measures the ripples or AC content in the output. It is obtained by dividing AC rms output with DC output. For full wave bridge rectifier it is 0.482. 4. If input frequency is 50Hz then ripple frequency of bridge full wave rectifier will be equal to a) 200Hz b) 50Hz c) 45Hz d) 100Hz View Answer 2 of 5

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Bridge Rectifier - Analog Circuits Questions and...

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Answer: d Explanation: Since in the output of bridge rectifier one half cycle is repeated hence frequency will twice as that of input frequency. That is 100Hz. 5. Transformer utilization factor of a bridge full wave rectifier is equal to a) 0.623 b) 0.812 c) 0.693 d) 0.825 View Answer Answer: b Explanation: Transformer utilization factor is the ratio of AC power delivered to load to the DC power rating. This factor indicates effectiveness of transformer usage by rectifier. For bridge full wave rectifier it is equal to 0.693. 6. If peak voltage on a bridge full wave rectifier circuit is 5V and diode cut-in voltage is 0.7, then peak inverse voltage on diode will be a) 4.3V b) 9.3V c) 8.6V d) 3.6V View Answer Answer: d Explanation: PIV is the maximum reveres bias voltage that can be appeared across a diode in the circuit. If PIV rating of the diode is less than this Value breakdown of diode may 3 of 5

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Bridge Rectifier - Analog Circuits Questions and...

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occur. Therefore, PIV rating of diode should be greater than PIV in the circuit. For bridge rectifier PIV is Vm-2VD. ie 5-1.4. 7. Efficiency of bridge full wave rectifier is a) 81.2% b) 50% c) 40.6% d) 45.3% View Answer Answer: a Explanation: It is obtained by taking ratio of DC power output to maximum AC power delivered to load. Efficiency of a rectifier is the effectiveness of rectifier to convert AC to DC. It is usually expressed in percentage. For bridge full wave rectifier, it is 81.2%. 8. In an bridge full wave rectifier, the input sine wave is 40sin100 ᴨt. The average output voltage is a) 22.73V b) 16.93V c) 25.47V d) 33.23V View Answer Answer: c Explanation: The equation of sine wave is in the form Em sin wt. Therefore, Em=40 Hence output voltage is 2Em/ ᴨ. That is 80/ ᴨ. 9. Number of diodes used in a full wave bridge rectifier is 4 of 5

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Bridge Rectifier - Analog Circuits Questions and...

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a) 1 b) 2 c) 4 d) 6 View Answer Answer: c Explanation: The model of bridge rectifier is same as weibridge. Like weinbridge needs 4 resistors bridge rectifier needs 4 diodes while center tap configuration requires only one. 10. In an bridge full wave rectifier, the input sine wave is 250sin100 ᴨt. The output ripple frequency of rectifier will be a) 50Hz b) 200Hz c) 100Hz d) 25Hz View Answer Answer: c Explanation: The equation of sine wave is in the form Em sin wt. Therefore, w = 100ᴨ that is, frequency f = w/2ᴨ = 50Hz Since output of full wave bridge rectifier have double the frequency of input, output frequency is 100Hz. Sanfoundry Global Education & Learning Series – Analog Circuits. To practice all areas of Analog Circuits, here is complete set of 1000+ Multiple Choice Questions and Answers.

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Series Clipper - Analog Circuits Questions and ...

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Series Clipper - Analog Circuits Questions and Answers by Manish 4-5 minutes

This set of Analog Circuits Multiple Choice Questions & Answers (MCQs) focuses on “Series Clipper-1”. 1. For a circuit given below, what will be the output if input signal is a sine wave shown below. (Use ideal diode model of diode)

a)

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Series Clipper - Analog Circuits Questions and ...

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b)

c)

d) View Answer Answer: c Explanation: In the circuit of serial clipper, it clips the negative half cycle and the output will only contain positive half cycle. In this problem input is a sine wave, hence output will be positive half of sine wave. 2. For a circuit given below, what will be the output if input signal is a triangular wave shown below. (Use ideal diode model of diode)

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a)

b)

c)

d) View Answer Answer: d Explanation: In the circuit of serial clipper, it clips the negative half cycle and the output will only contain positive half cycle. In this problem input is a triangular wave, hence output will be positive half of triangular wave. 3. For a circuit given below, what will be the output if input 3 of 11

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Series Clipper - Analog Circuits Questions and ...

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signal is a square wave shown below. (Use ideal diode model of diode)

a)

b)

c)

d) View Answer Answer: d

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Explanation: In the circuit of serial clipper, it clips the negative half cycle and the output will only contain positive half cycle. In this problem input is a square wave, hence output will be positive half of square wave. 4. A simple circuit diagram for a serial clipper is given below. What will be the transfer characteristics of the circuit? (Use constant voltage drop model of diode)

a)

b)

c)

d)

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View Answer Answer: a Explanation: Since at constant voltage drop model voltage drop across diode at forward bias is a constant. In this circuit if input is negative diode is reverse bias hence no current. So for negative input output is zero. For positive input Vout will be equal to input with a voltage drop of VD. 5. For a circuit given below, what will be the output if input signal is a sine wave shown below. (Use ideal diode model of diode)

a)

b)

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c)

d) View Answer Answer: d Explanation: In the circuit of serial clipper, it clips the positive half cycle and the output will only contain negative half cycle. In this problem input is a sine wave, hence output will be negative half of sine wave. 6. For a circuit given below, what will be the output if input signal is a triangular wave shown below. (Use ideal diode model of diode)

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a)

b)

c)

d) View Answer Answer: a Explanation: In the circuit of serial clipper, it clips the positive half cycle and the output will only contain negative half cycle. In this problem input is a triangular wave, hence output will be negative half of triangular wave. 7. For a circuit given below, what will be the output if input signal is a square wave shown below. (Use ideal diode model of diode)

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a)

b)

c)

d) View Answer Answer: c Explanation: In the circuit of serial clipper, it clips the positive half cycle and the output will only contain negative

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Series Clipper - Analog Circuits Questions and ...

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half cycle. In this problem input is a square wave, hence output will be negative half of square wave. 8. A simple circuit diagram for a serial clipper is given below. What will be the transfer characteristics of the circuit? (Use constant voltage drop model of diode)

a)

b)

c)

d) View Answer Answer: b Explanation: Since at constant voltage drop model voltage 10 of 11

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Series Clipper - Analog Circuits Questions and ...

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drop across diode at forward bias is a constant. In this circuit if input is positive diode is reverse bias hence no current. So for positive input output is zero. For negative input Vout will be equal to input with a voltage drop of VD. Sanfoundry Global Education & Learning Series – Analog Circuits. To practice all areas of Analog Circuits, here is complete set of 1000+ Multiple Choice Questions and Answers.

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Analog Circuits Interview Questions and Answer...

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Analog Circuits Interview Questions and Answers for Experienced by Manish 5-7 minutes

This set of Analog Circuits Interview Questions and Answers for Experienced people focuses on “Series Clipper-2”. 1. In the following clipper circuit resistance R1 and R2 is 1k. Voltage V is 1V. Cut-in voltage of diode is 0.7V. What will be the output of the system if Vin is the signal given below? (Use constant voltage drop model for diode)

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a)

b)

c)

d) View Answer Answer: a Explanation: Total voltage in the circuit is VinVD-V = 5sint -0.7 – 1 = 5sint -1.7 The voltage across resistor R2 = Vtotalx R2/(R1+R2) = (5sint -1.7) 1/2 Maximum value of output will be 5-1.7/2 = 1.65V The output will be positive half of sine wave with an upward shift of 1V. In the diagram below Red is input and green is output

. 2. In the following clipper circuit resistance R1 and R2 is 1k.

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Analog Circuits Interview Questions and Answer...

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Voltage V is -1V. Cut-in voltage of diode is 0.7V. What will be the output of the system if Vin is the signal given below? (Use constant voltage drop model for diode)

a)

b)

c)

d) View Answer Answer: b Explanation: Total voltage in the circuit is VinVD-V = 5sint -0.7 + 1 = 5sint +0.3 The voltage across 3 of 14

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Analog Circuits Interview Questions and Answer...

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resistor R2 = Vtotal x R2/(R1+R2) = (5sint +0.3) 1/2 Maximum value of output will be 5+0.3/2 = 2.65V The output will be positive half of sine wave with a downward shift of 1V. In the diagram below Red is input and green is output

. 3. In the following clipper circuit resistance R1 and R2 is 1k. Voltage V is 1V. Cut-in voltage of diode is 0.7V. What will be the output of the system if Vin is the signal given below? (Use constant voltage drop model for diode)

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a)

b)

c)

d) View Answer Answer: c Explanation: Total voltage in the circuit is VinVD+V = 5sint -0.7 +1 = 5sint +0.3 The voltage across resistor R2 = Vtotalx R2/(R1+R2) = (5sint +0.3) 1/2 Maximum value of output will be 5+0.3/2 = 2.65V The output will be positive half of sine wave with maximum voltage of 2.65V In the diagram below Red is input and green is output.

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Analog Circuits Interview Questions and Answer...

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4. In the following clipper circuit resistance R1 and R2 is 1k. Voltage V is 1V. Cut-in voltage of diode is 0.7V. What will be the output of the system if Vin is the signal given below? (Use constant voltage drop model for diode)

a)

b)

c)

d) View Answer 6 of 14

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Analog Circuits Interview Questions and Answer...

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Answer: d Explanation: Total voltage in the circuit is VinVD-V = 5sint -0.7 – 1 = 5sint -1.7 The voltage across resistor R2 = Vtotalx R2/(R1+R2) = (5sint -1.7) 1/2 Maximum value of output will be 5-1.7/2 = 1.65V The output will be positive half of sine wave with reduction of 1.7V and maximum of 2.15V. In the diagram below Red is input and green is output.

5. In the following clipper circuit resistance R1 and R2 is 1k. Voltage V1 is 1V and V2 is 1.5V. Cut-in voltage of diode is 0.7V. What will be the output of the system if Vin is the signal given below? (Use constant voltage drop model for diode)

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a)

b)

c)

d) View Answer Answer: a Explanation: Total voltage in the circuit is VinVD-V1-V2 = 5sint -0.7 – 1-1.5 = 5sint -3.2 The voltage across resistor R2 = Vtotalx R2/(R1+R2) = (5sint -3.2) 1/2 Maximum value of output will be 5-3.2/2 = 0.9V. The output will be positive half of sine wave with reduction of 3.2V and 8 of 14

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Analog Circuits Interview Questions and Answer...

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maximum of 0.9V. In the diagram below Red is input and green is output.

6. In the following clipper circuit resistance R1 and R2 is 1k. Voltage V1 is -1.5V and V2 is 1V. Cut-in voltage of diode is 0.7V. What will be the output of the system if Vin is the signal given below? (Use constant voltage drop model for diode)

a)

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Analog Circuits Interview Questions and Answer...

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b)

c)

d) View Answer Answer: b Explanation: Total voltage in the circuit is VinVD-V1-V2 = 5sint -0.7 +1.5– 1 = 5sint -0.2 The voltage across resistor R2 = Vtotalx R2/(R1+R2) = (5sint -0.2) 1/2 Maximum value of output will be 5-0.2/2 = 2.4V. The output will be positive half of sine wave with a maximum of 2.4V. In the diagram below Red is input and green is output.

7. In the following clipper circuit resistance R1 and R2 is 1k. Voltage V1 is 1.5V and V2 is -1V. Cut-in voltage of diode is 0.7V. What will be the output, Vout of the system if Vin is the signal given below? (Use constant voltage drop model for diode)

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a)

b)

c)

d) View Answer Answer: c Explanation: Total voltage in the circuit is Vin-VDV1-V2 = 5sint -0.7 -1.5+1 = 5sint -1.2 The voltage across resistor R2 = Vtotal x R2/(R1+R2) = (5sint -1.2) 1/2 Maximum value of output will be 5-1.2/2 = 1.9V. The output will be positive half of sine wave with a maximum of 1.9V. 11 of 14

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Analog Circuits Interview Questions and Answer...

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In the diagram below Red is input and green is output.

8. In the following clipper circuit resistance R1 and R2 is 1k. Voltage V1 is 1.5V and V2 is 1 V. Cut-in voltage of diode is 0.7V. What will be the output, Vout of the system if Vin is the signal given below? (Use constant voltage drop model for diode)

a)

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b)

c)

d) View Answer Answer: d Explanation: Total voltage in the circuit is VinVD-V1-V2 = 5sint -0.7 -1.5-1 = 5sint -3.2 The voltage across resistor R2 = Vtotal x R2/(R1+R2) = (5sint -3.2) 1/2 Maximum value of output will be 5-3.2/2 = 0.9V. The output will be positive half of sine wave with a maximum of 0.9V and with an upward shift of 1V. In the diagram below Red is input and green is output.

Sanfoundry Global Education & Learning Series – Analog Circuits. To practice all areas of Analog Circuits for Interviews, here

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is complete set of 1000+ Multiple Choice Questions and Answers.

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Parallel Clipper - Analog Circuits Questions and...

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Parallel Clipper - Analog Circuits Questions and Answers by Manish 5-6 minutes

This set of Analog Circuits Multiple Choice Questions & Answers (MCQs) focuses on “Parallel Clipper-1”. 1. For a circuit given below, what will be the output if input signal is a sine wave shown below. (Use ideal diode model of diode)

a)

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b)

c)

d) View Answer Answer: d Explanation: In the circuit of parallel clipper, diode blocks the negative half cycle and the output will only contain negative half cycle. In this problem input is a sine wave, hence output will be negative half of sine wave. 2. For a circuit given below, what will be the output if input signal is a triangular wave shown below. (Use ideal diode model of diode)

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a)

b)

c)

d) View Answer Answer: a Explanation: In the circuit of parallel clipper, diode blocks the negative half cycle and thus output will only contain negative half cycle. In this problem input is a triangular wave, hence output will be negative half of triangular wave. 3. For a circuit given below, what will be the output if input

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signal is a square wave shown below. (Use ideal diode model of diode)

a)

b)

c)

d)

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View Answer Answer: c Explanation: In the circuit of parallel clipper, diode blocks the negative half cycle and thus output will only contain negative half cycle. In this problem input is a square wave, hence output will be negative half of square wave. 4. A simple circuit diagram for a serial clipper is given below. What will be the transfer characteristics of the circuit? (Use ideal diode model of diode)

a)

b)

c)

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d) View Answer Answer: c Explanation: Since at constant voltage drop model voltage drop across diode at forward bias is a constant. In this circuit if input is negative diode is reverse bias hence no current. For positive input diode conducts and hence for positive input output is zero. For negative input vout will be equal to input. 5. For a circuit given below, what will be the output if input signal is a sine wave shown below. (Use ideal diode model of diode)

a)

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b)

c)

d) View Answer Answer: c Explanation: In the circuit of parallel clipper, diode bocks the positive half cycle and thus output will only contain positive half cycle. In this problem input is a sine wave, hence output will be positive half of sine wave. 6. For a circuit given below, what will be the output if input signal is a triangular wave shown below. (Use ideal diode model of diode)

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a)

b)

c)

d) View Answer Answer: d Explanation: In the circuit of parallel clipper, diode blocks the positive half cycle and the output will only contain positive half cycle. In this problem input is a triangular wave, hence output will be positive half of triangular wave. 7. For a circuit given below, what will be the output if input

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signal is a square wave shown below. (Use ideal diode model of diode)

a)

b)

c)

d)

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View Answer Answer: d Explanation: In the circuit of parallel clipper, diode blocks the positive half cycle and thus output will only contain positive half cycle. In this problem input is a square wave, hence output will be positive half of square wave. 8. A simple circuit diagram for a serial clipper is given below. What will be the transfer characteristics of the circuit? (Use constant voltage drop model of diode)

a)

b)

c)

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d) View Answer Answer: d Explanation: Since at constant voltage drop model voltage drop across diode at forward bias is a constant. In this circuit if input is positive diode is reverse bias hence no current. For negative input diode conducts and hence for negative input output is zero. For positive input vout will be equal to input. 9. For a circuit given below, what will be the output if input signal is a sine wave shown below. (Use constant voltage drop diode model of diode)

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a)

b)

c)

d) View Answer Answer: d Explanation: In the circuit of parallel clipper, diode blocks the positive half cycle and the output will only contain positive half cycle. In this problem input is a square wave, hence output will be positive half of square wave. But since

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Parallel Clipper - Analog Circuits Questions and...

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diode is in constant voltage drop model at forward bias diode has a potential drop of Vd. This will also reflect in the output and hence at negative input output voltage will be a constant and equals to Vd. 10. For a circuit given below, what will be the output if input signal is a sine wave shown below. (Use constant voltage drop diode model of diode)

a)

b)

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Parallel Clipper - Analog Circuits Questions and...

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c)

d) View Answer Answer: b Explanation: In the circuit of parallel clipper, diode blocks the negative half cycle and the output will only contain negative half cycle. In this problem input is a square wave, hence output will be negative half of square wave. But since diode is in constant voltage drop model at forward bias diode has a potential drop of Vd. This will also reflect in the output and hence at positive input output voltage will be a constant and equals to Vd. Sanfoundry Global Education & Learning Series – Analog Circuits. To practice all areas of Analog Circuits, here is complete set of 1000+ Multiple Choice Questions and Answers.

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Analog Circuits Test - Sanfoundry

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Analog Circuits Test - Sanfoundry by Manish 6-7 minutes

This set of Analog Circuits test focuses on “Parallel Clipper-2”. 1. For the circuit given below, which of the following diagram represent Vout if Vin is the signal shown below? (Use constant voltage drop model of diode and take cut-in voltage as 0.7V)

a)

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c)

d) View Answer Answer: c Explanation: When diode D is forward biased it conducts current and hence voltage drop across is VD. For positive half cycle of the input diode conducts and Vout becomes VD. The linear portion of the graph is the point where Vin is positive is because up to 0.7V diode will not conduct and input as such appears on output. When diode is reverse bias there is no current through the diode and hence the voltage will be same as that across the resistor which is connected to ground. It is Vinx1k/(1k+1k). The minimum voltage across it will be -5/2 = -2.5V and maximum voltage at output is 0.7V In the diagram, red shows input and green shows output

.

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2. For the circuit given below, which of the following diagram represent Vout if Vin is the signal shown below? (Use constant voltage drop model of diode and take cut-in voltage as 0.7V)

a)

b)

c)

d) 3 of 15

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View Answer Answer: c Explanation: When diode D is forward biased it conducts current and hence voltage drop across is VD. For positive half cycle of the input diode conducts and Vout becomes VD. When diode is reverse bias there is no current through the diode and hence the voltage will be same as that across the resistor which is connected to ground. It is Vinx1k/(1k+1k). The minimum voltage across it will be -5/2 = -2.5V and maximum voltage at output is 0.7V. 3. For the circuit given below, which of the following diagram represent Vout if Vin is the signal shown below? (Use constant voltage drop model of diode and take cut-in voltage as 0.7V)

a)

b) 4 of 15

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c)

d) View Answer Answer: d Explanation: When diode D is forward biased it conducts current and hence voltage drop across is VD. For negative half cycle of the input diode conducts and Vout becomes VD. When diode is reverse bias there is no current through the diode and hence the voltage will be same as that across the resistor which is connected to ground. It is Vinx1k/(1k+1k). The maximum voltage across it will be 5/2 = 2.5V and minimum voltage at output is -0.7V In the diagram, red shows input and green shows output.

4. For the circuit given below, which of the following diagram represent Vout if Vin is the signal shown below? (Use constant voltage drop model of diode and take cut-in voltage as 0.7V)

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a)

b)

c)

d) View Answer Answer: d Explanation: When diode D is forward biased it conducts current and hence voltage drop across is VD. 6 of 15

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For negative half cycle of the input diode conducts and Vout becomes VD. When diode is reverse bias there is no current through the diode and hence the voltage will be same as that across the resistor which is connected to ground. It is Vinx1k/(1k+1k). The maximum voltage across it will be 5/2 = 2.5V and minimum voltage at output is -0.7V. 5. For the circuit given below, which of the following diagram represent Vout if Vin is the signal shown below? (Use constant voltage drop model of diode and take cut-in voltage as 0.7V)

a) 5v b) 2v c) 0V d) 10v View Answer Answer: c Explanation: In circuit of parallel clipper voltage across the diode D2 will be same as a simple parallel clipper. The output of the circuit is null because the output of diode D2 is negative and diode D will not conduct negative voltage. 6. For the circuit given below, which of the following diagram represent Vout if Vin is the signal shown below? 7 of 15

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(Use constant voltage drop model of diode and take cut-in voltage as 0.7V)

a)

b)

c)

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d) View Answer Answer: a Explanation: Answer is first graph, because the diode D2 gives negative output and this can be obtained through the diode D. Sine it es through diode D it will have a voltage drop of VD. 7. For the circuit given below, which of the following diagram represent Vout if Vin is the signal shown below? (Use constant voltage drop model of diode and take cut-in voltage as 0.7V)

a)

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b)

c)

d) View Answer Answer: b Explanation: Here in the circuit since both diodes are in opposite direction both positive and negative cycles will through diodes. Since both diodes conduct every time the voltage across diodes will always be 0.7V and sign depends on the cycle. 8. For the circuit given below, which of the following diagram represent Vout if Vin is the signal shown below? (Use constant voltage drop model of diode and take cut-in voltage as 0.7V)

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a)

b)

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c)

d) View Answer Answer: d Explanation: Here in the circuit since both diodes are in opposite direction both positive and negative cycles will through diodes. Since both diodes conduct every time the voltage across diodes will always be 0.7V and sign depends on the cycle. 9. For the circuit given below, which of the following diagram represent Vout if Vin is the signal shown below? (Use constant voltage drop model of diode and take cut-in voltage as 0.7V)

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a)

b)

c)

d) View Answer Answer: c Explanation: The circuit can be simplified using star –delta conversion of resistors. The three resistor network can be solved by delta – star equivalent which

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gives a simplified form as former questions afer solVing star –delta the circuit will look like as follows

Hence the circuit is simplified. When diode D is forward biased it conducts current and hence voltage drop across is VD. For negative half cycle of the input diode conducts and Vout becomes VD. When diode is reverse bias there is no current through the diode and hence the voltage will be same as that across the resistor which is connected to ground. It is Vinx333.3/(0.33k+1.33k). The maximum voltage across it will be 0.7V and minimum voltage at output is -1V In the diagram, red shows input and green shows output.

Sanfoundry Global Education & Learning Series – Analog Circuits. To practice all areas of Analog Circuits for tests, here is 14 of 15

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complete set of 1000+ Multiple Choice Questions and Answers.

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Parallel Clipper Circuit with Reference Voltage...

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Parallel Clipper Circuit with Reference Voltage Questions and Answers by Manish 6-8 minutes

his set of Analog Circuits Multiple Choice Questions & Answers (MCQs) focuses on “Parallel Clipper Circuit with Reference Voltage-1”. 1. Which of the following graphs will be appropriate to describe output V of the circuit given below? The voltage VB is 1V and input to the circuit Vin is 5sint. The resistance R is 1K. (Use constant voltage drop model for diode and take cut-in voltage as 0.7V)

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Parallel Clipper Circuit with Reference Voltage...

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a)

b)

c)

d) View Answer Answer: d Explanation: In the circuit VB is in the forward direction for diode. At positive cycle of Vin diode will be forward biased up to Vin = 0.3V. Up to 0.3V output is 0.3V and after this diode is reverse biased and output follows input. In negative cycle diode is always forward biased and output will be equal to 1-0.7 = 0.3V. 2. Which of the following graphs will be appropriate to 2 of 16

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Parallel Clipper Circuit with Reference Voltage...

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describe output V of the circuit given below? The voltage VB is 1V and input to the circuit Vin is 5sint. The resistance R is 1K. (Use constant voltage drop model for diode and take cut-in voltage as 0.7V)

a)

b)

c)

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Parallel Clipper Circuit with Reference Voltage...

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d) View Answer Answer: c Explanation: In the circuit VB is in the forward direction for diode. At positive cycle of Vin diode will be forward biased up to Vin = 0.3V. Up to 0.3V output is 0.7V and after this diode is reverse biased and output follows input. In negative cycle diode is always forward biased and output will be equal to 0.7V in reverse direction. In the following diagram red represents input and green represents output.

3. Which of the following graphs will be appropriate to describe output V of the circuit given below? The voltage VB is 1V and input to the circuit Vin is 5sint. The resistance R is 1K. (Use constant voltage drop model for diode and take cut-in voltage as 0.7V)

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a)

b)

c)

d) View Answer Answer: b Explanation: In the circuit VB is in the reverse direction for diode. At positive cycle of Vin diode will be forward biased 5 of 16

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Parallel Clipper Circuit with Reference Voltage...

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from Vin = 1.7V. Up to 1.7V output is 5sint-1V and after this diode is forward biased and output will be 0.7V. In negative cycle diode is always reverse biased and output will be equal to 5sint-1. 4. Which of the following graphs will be appropriate to describe output Vout of the circuit given below? The voltage V1 is 1V, V2 is 1V and input to the circuit V is 5sint. Assume both diodes are identical. (Use constant voltage drop model for diode and take cut-in voltage as 0.7V)

a)

b)

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Parallel Clipper Circuit with Reference Voltage...

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c)

d) View Answer Answer: d Explanation: In the circuit V1 and V2 are in the forward direction for diodes. Since these are parallel we can consider this as a single diode and source. At positive cycle of Vin diode will be forward biased up to Vin = 0.3V. Up to 0.3V output is 0.3V and after this diode is reverse biased and output follows input. In negative cycle diode is always forward biased and output will be equal to 1-0.7 = 0.3V. 5. Which of the following graphs will be appropriate to describe output Vout of the circuit given below? The voltage V1 is 1V, V2 is 1V and input to the circuit V is 5sint. Assume both diodes are identical. (Use constant voltage drop model for diode and take cut-in voltage as 0.7V)

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a)

b)

c)

d) View Answer Answer: b

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Parallel Clipper Circuit with Reference Voltage...

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Explanation: In this circuit diodes are placed opposite to each other. So output will be determined by diode which is in forward bias. At negative cycle first diode will be forward biased hence output will be 0.3V. At positive cycle diode will be reverse bias up to 1.7V so input follows output and after this it is constant and equals to 1.7V. 6. Which of the following graphs will be appropriate to describe output Vout of the circuit given below? The voltage V1 is 1V, V2 is 1V and input to the circuit V is 5sint. Assume both diodes are identical. (Use constant voltage drop model for diode and take cut-in voltage as 0.7V)

a)

b)

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Parallel Clipper Circuit with Reference Voltage...

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c)

d) View Answer Answer: c Explanation: Since both diodes are in reverse mode with respect to V1 and V2, at negative V output follows input. At positive cycle up to 1.7V diodes are in reverse bias mode and after this they becomes forward biased and output becomes a constant and equals to 1.7V. 7. Which of the following graphs will be appropriate to describe output Vout of the circuit given below? The voltage V1 is 1V, V2 is 1.5V and input to the circuit V is 5sint. Assume both diodes are identical. (Use constant voltage drop model for diode and take cut-in voltage as 0.7V)

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a)

b)

c)

d) View Answer Answer: b Explanation: In this circuit diodes are placed opposite to each other. So output will be determined by diode which is 11 of 16

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Parallel Clipper Circuit with Reference Voltage...

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in forward bias. At negative cycle first diode will be forward biased hence output will be 0.3V. At positive cycle diode will be reverse bias up to 1.7V so input follows output and after this it is constant and equals to 1.7V. 8. Which of the following graphs will be appropriate to describe output Vout of the circuit given below? The voltage V1 is 1V, V2 is 1V and input to the circuit V is 5sint. (Use constant voltage drop model for diode and take cut-in voltage as 0.7V)

a)

b)

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Parallel Clipper Circuit with Reference Voltage...

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c)

d) View Answer Answer: a Explanation: At positive cycle of V, V1 opposes hence output will be 5sint-1. For negative half cycle of V, output will be 0.3V because diode is already in forward bias. 9. Which of the following graphs will be appropriate to describe output Vout of the circuit given below? The voltage V1 is 1V, V2 is 1V and input to the circuit V is 5sint. (Use constant voltage drop model for diode and take cut-in voltage as 0.7V)

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Parallel Clipper Circuit with Reference Voltage...

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a)

b)

c)

d) View Answer Answer: a Explanation: For negative half cycle diode is forward biased and hence output is 0.3V. For positive half cycle output will be (5sint+1)/2(Since voltage divided in between two 1K, third one has no effect). Hence maximum voltage will be 6/2 = 3V. 10. Which of the following graphs will be appropriate to describe output Vout of the circuit given below? The voltage V1 is 1V, V2 is 1V and input to the circuit V is 14 of 16

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Parallel Clipper Circuit with Reference Voltage...

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5sint. (Use constant voltage drop model for diode and take cut-in voltage as 0.7V)

a)

b)

c)

d) View Answer Answer: d Explanation: For negative half cycle of V and up to 3.4V in positive half cycle since diode is in reverse bias output will be (5sint-1)/2 Since voltage divided in between 15 of 16

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two 1K, third one has no effect). Hence minimum voltage will be -4/2 = -2V. After 3.4V output becomes 1.7V.

Sanfoundry Global Education & Learning Series – Analog Circuits. To practice all areas of Analog Circuits, here is complete set of 1000+ Multiple Choice Questions and Answers.

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Analog Circuits Quiz - Sanfoundry

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Analog Circuits Quiz - Sanfoundry by Manish 5-7 minutes

This set of Analog Circuits Quiz focuses on “Parallel Clipper Circuit with Reference Voltage-2”. 1. What will be the output of the circuit Vout if the voltage V2 is 1V and input to the circuit V is 5sint? (Use constant voltage drop model for diode and take cut-in voltage as 0.7V)

a)

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b)

c)

d) View Answer Answer: b Explanation: V2 is forward bias to diode. At positive cycle of V diode is reverse biased and output will be the half of input (Since input is divided by two 1k resistors). At negative cycle output will be 0.3 because diode is forward biased. 2. What will be the output of the circuit Vout if the voltage V2 is 1V and input to the circuit V is 5sint? (Use constant voltage drop model for diode and take cut-in voltage as 0.7V)

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a)

b)

c)

d) View Answer Answer: c Explanation: V2 is reverse bias to diode. When diode is forward biased output will be 1.7V all other time output will be 5sint/2(Since input is divided by two 1k resistors). 3 of 15

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Analog Circuits Quiz - Sanfoundry

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3. What will be the output of the circuit Vout if the voltage V2 is 1V and input to the circuit V is 5sint? (Use constant voltage drop model for diode and take cut-in voltage as 0.7V)

a)

b)

c)

d) View Answer Answer: c 4 of 15

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Analog Circuits Quiz - Sanfoundry

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Explanation: V2 is reverse bias to diode. When diode is forward biased output will be 1.7V all other time output will be 5sint/2(Since input is divided by two 1k resistors, here third resistor is insignificant since diode is not real). 4. What will be the output of the circuit Vout if the voltage V2 is 1V and input to the circuit V is 5sint? (Use constant voltage drop model for diode and take cut-in voltage as 0.7V)

a)

b)

c)

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d) View Answer Answer: d Explanation: V2 is forward bias to diode. At positive cycle of V diode is reverse biased and output will be the half of input (Since input is divided by two 1k resistors, here third resistor is insignificant since diode is not real). At negative cycle output will be 0.3 because diode is forward biased. 5. What will be the output of the circuit Vout if the voltage V2 is 1V and input to the circuit V is 5sint? (Use constant voltage drop model for diode and take cut-in voltage as 0.7V)

a)

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b)

c)

d) View Answer Answer: a Explanation: We must solve this problem using star- delta conversion. If not this will be difficult to solve. For positive half cycle (above 1.5V) diode is reverse bias hence output will be 5sintx0.33/1.66. Maximum voltage will be 5×0.198 = 0.99V For voltage < 1.5V diode is forward biased and hence output will be 0.3V. 6. What will be the output of the circuit Vout if the voltage V2 is 0.1V and input to the circuit V is 5sint? (Use constant voltage drop model for diode and take cut-in voltage as 0.7V)

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a)

b)

c)

d) View Answer Answer: a Explanation: We must solve this problem using star- delta conversion. If not this will be difficult to solve. After conversion circuit diagram will be as follows 8 of 15

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Analog Circuits Quiz - Sanfoundry

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For positive half cycle of V, diode will be forward biased if V is greater than 2.51V (that is we need 1.7V at output and therefore input must be 0.8×1.66/0.33 = 4V. For negative half cycle output follows input with a compression of 0.198. Therefore, minimum voltage will be -5×0.198 = -0.99V. 7. What will be the output of the circuit Vout if the voltage V2 is 1V and input to the circuit V is 5sint? (Use constant voltage drop model for diode and take cut-in voltage as 0.7V)

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a)

b)

c)

d) View Answer

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Answer: c Explanation: Since V2 is reverse bias to diode, the peak of output will be 1.7V. It is because after 1.7V diode becomes forward bias and voltage drop across diode becomes a constant. For V<1.7 output follows input because diode is in reverse bias mode. 8. What will be the output of the circuit Vout if the voltage V2 is 1V and input to the circuit V is 5sint? (Use constant voltage drop model for diode and take cut-in voltage as 0.7V)

a)

b) 11 of 15

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c)

d) View Answer Answer: b Explanation: Since V2 is forward bias to diode, the peak of output will be 5V. It is because after 0.3V diode becomes reverse bias and output follows input. For V<0.3 voltage drop across diode becomes a constant because diode is in forward bias mode and output will be 0.3V (1-0.7V). 9. What will be the output of the circuit Vout if the voltage V1 is 1V, V2 is 1V and input to the circuit V is 5sint? (Use constant voltage drop model for diode and take cut-in voltage as 0.7V)

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a)

b)

c)

d) View Answer Answer: d 13 of 15

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Explanation: Since V2 is reverse bias to diode, the peak of output will be 1.7V. It is because after 1.7V diode becomes forward bias and voltage drop across diode becomes a constant. For V<1.7 output follows input because diode is in reverse bias mode. Input will be 5sint-1. So minimum output voltage is -6V. 10. What will be the output of the circuit Vout if the voltage V1 is 1V, V2 is 1V and input to the circuit V is 5sint? (Use constant voltage drop model for diode and take cut-in voltage as 0.7V)

a)

b)

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c)

d) View Answer Answer: c Explanation: Since V2 is forward bias to diode, the peak of output will be 3V (5-1-1). It is because after 1.3V diode becomes reverse bias and output follows input (5sint-2). For V<1.3V voltage drop across diode becomes a constant because diode is in forward bias mode and output will be 0.7V. Sanfoundry Global Education & Learning Series – Analog Circuits. To practice all areas of Analog Circuits for Quizzes, here is complete set of 1000+ Multiple Choice Questions and Answers.

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Diode Approximations & Series Connection Que...

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Diode Approximations & Series Connection Questions and Answers by Manish 4-5 minutes

This set of Analog Circuits Multiple Choice Questions & Answers (MCQs) focuses on “Diode Approximations and Series Connection”. 1. Which of the following models of semiconductor diode is the most widely used for the purpose of calculation? a) Approximate Equivalent Model b) Ideal Diode Model c) Piecewise Linear Model d) None of the mentioned View Answer Answer: a Explanation: Approximate Equivalent model not only saves time and efforts but also provides results with considerable amount of accuracy. 2. Statement-1: Piecewise linear model is generally not used for diode analysis. Statement-2: The value of Rav is negligible as compared to 1 of 8

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Diode Approximations & Series Connection Que...

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the load resistance. Which of the following holds true? a) Statement-1 is true, Statement-2 is true and Statement-2 is a proper explanation for Statement-1 b) Statement-1 is true, Statement-2 is true and Statement-2 is not a proper explanation for Statement-1 c) Statement-1 is true, Statement-2 is false d) Statement-1 is false, Statement-2 is true View Answer Answer: a Explanation: Piecewise linear model involves a line with a slope equal to 1/Rav. As Rav is low, 1/ Rav is high and the slope becomes almost equal to infinity and hence, it approaches the equivalent circuit model and hence, piecewise linear model isn’t generally used. 3. From the given circuit diagram, considering the diode to be a silicon semiconductor diode, what is the magnitude of diode current?

a) 43 mA b) 0 mA c) 4.3 mA d) 5 mA View Answer

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Diode Approximations & Series Connection Que...

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Answer: c Explanation: ID = (V-VD)/R = 4.3 mA 4. From the given circuit diagram, what is the value of diode current?

a) 8 mA b) 7.3 mA c) 0 mA d) 7 mA View Answer Answer: c Explanation: As both the diodes are reverse biased, the current in the circuit is zero. 5. From the given circuit diagram, what is the value of diode current?

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Diode Approximations & Series Connection Que...

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a) 8 mA b) 0 mA c) 7.3 mA d) 7 mA View Answer Answer: b Explanation: As the silicon diode in the circuit is reverse biased, hence the current in the circuit is zero. 6. From the given circuit diagram, what is the value of diode current?

a) 8 mA b) 0 mA c) 7.3 mA d) 7 mA View Answer Answer: d Explanation: ID = (V-VD1-VD2)/R = 7 mA 7. From the given circuit diagram, what is the value of diode current?

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Diode Approximations & Series Connection Que...

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a) 2 mA b) 0 mA c) 1.3 mA d) 1 mA View Answer Answer: b Explanation: As the sum of voltage drops in the diodes is equal to the source voltage, the current in the circuit is zero. 8. From the given circuit diagram, what is the value of voltage across the resistor?

a) 2 V b) 1.3 V c) 1 V d) 0 V View Answer

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Answer: d Explanation: As the sum of voltage drops in the diodes is equal to the source voltage, the voltage cross the resistor is zero. 9. From the given circuit diagram, what is the value of diode current?

a) 2.425 mA b) 5.2 mA c) 2.325 mA d) 0 mA View Answer Answer: c Explanation: Here, ID=(V-VD)/R = 2.325 mA 10. From the given circuit diagram, what is the value of voltage across R2?

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a) 9.324 V b) 5.3 V c) 0 V d) 5.8125 V View Answer Answer: d Explanation: Here, VR2 = I x R2 = 5.8125 V 11. From the given circuit diagram, what is the voltage across diode?

a) 10 V b) 5 V c) 0.7 V d) 0 V View Answer Answer: a Explanation: As the diode is reverse biased, the current in the circuit is zero and hence the voltage across the diode is equal to the source voltage = 10 V 12. From the given circuit diagram, what is the value of diode current?

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a) 2.425 mA b) 5.2 mA c) 2.325 mA d) 0 mA View Answer Answer: d Explanation: As the diode is reverse biased, the current in the circuit is zero. Sanfoundry Global Education & Learning Series – Analog Circuits. To practice all areas of Analog Circuits, here is complete set of 1000+ Multiple Choice Questions and Answers.

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Diode Clipper & Clamper - Analog Circuits Ques...

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Diode Clipper & Clamper - Analog Circuits Questions and Answers by Manish 4-5 minutes

This set of Analog Circuits Multiple Choice Questions & Answers (MCQs) focuses on “Diode Clipper and Clamper”. 1. What is the circuit in the given diagram called?

a) Clipper b) Clamper c) Rectifier d) None of the mentioned View Answer Answer: a Explanation: The given circuit due to the presence of a reference voltage source, clips the input waveform and hence it is a clipper. 2. 1. What is the circuit in the given diagram called?

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a) Clipper b) Clamper c) Rectifier d) None of the mentioned View Answer Answer: b Explanation: The given circuit clamps the input waveform to a fixed DC level and hence it is a clamper. 3. For a sinusoidal input of 20 Vpeak to the given circuit, what is the peak value of the output waveform?

a) 20 V b) 25 V c) 0 V d) -25 V View Answer Answer: b Explanation: In the given circuit, the output becomes zero

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for vi less than -5 V. Hence, the peak value of the output is 25 V owing to the additive effect of V for vi. 4. For the given circuit for a 20 Vpeak sinusoidal input vi, what is the value of vi at which the clipping begins?

a) 5 V b) 0 V c) -5 V d) Clipping doesn’t occur View Answer Answer: c Explanation: Considering the connection of diode, it is evident that the diode becomes reverse biased when vi < -5 V. Hence, clipping starts at -5 V. 5. For a sinusoidal input of 20 Vpeak to the given circuit, what is the minimum value of the output waveform?

a) 20 V b) 25 V c) -25 V

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d) 0 V View Answer Answer: d Explanation: The given circuit is a clipper which cuts off a part of the negative cycle of the input sinusoid i.e. the output becomes zero for a certain region of the input waveform. Hence, the minimum value is 0 V. 6. For the given input waveform to the given circuit, what is the peak value of the output waveform?

a) 0 V b) 16 V c) 12 V d) None of the mentioned View Answer Answer: b Explanation: In the given circuit, the diode is in the off stage when vi > 4 V. Hence, when vi > 4 V, vo = vi and hence the peak value of vo = the peak value of vi = 16 V. 7. For the given input waveform to the given circuit, what is the minimum value of the output waveform?

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a) 0 V b) 16 V c) 12 V d) None of the mentioned View Answer Answer: a Explanation: The given circuit is a clipper which cuts off a certain part of the input waveform i.e. the output becomes zero for a certain region of the input waveform. Hence, the minimum value is 0 V. 8. Which of the following is not a necessary component in a clamper circuit? a) Diode b) Capacitor c) Resistor d) Independent DC Supply View Answer Answer: d Explanation: Diode, Capacitor and Resistor are necessary to build a clamper circuit. An independent DC supply is required to bring an additional shift. 9. For the given circuit, what is the minimum peak value of the output waveform if the input waveform is 10V square

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wave with switching time of 1 second? Assume that the input switches between +10V and -10V DC levels.

a) 0 V b) -5 V c) -20 V d) -10 V View Answer Answer: c Explanation: For the positive half of the input, the diode is in the on state and hence acts as a short circuit and hence vo = 0 V. For the negative half cycle, the resistor receives voltage input both from the source and the capacitor which is charged during the positive half of the input. Hence, vo = -20 V. 10. For the given circuit and input waveform, the peak value of the output is +30V.

a) True

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b) False View Answer Answer: a Explanation: The given circuit is a clamper with an independent DC supply of +10 V. Keeping in mind the connection of the diode and the DC supply, we see that the output waveform is clamped at +10V i.e. it shifts up by +10V. Hence, the maximum value of vo=+30 V. Sanfoundry Global Education & Learning Series – Analog Circuits. To practice all areas of Analog Circuits, here is complete set of 1000+ Multiple Choice Questions and Answers.

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Diode Gates & Rectifiers - Analog Circuits Ques...

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Diode Gates & Rectifiers - Analog Circuits Questions and Answers by Manish 5-6 minutes

This set of Analog Circuits Multiple Choice Questions & Answers (MCQs) focuses on “Diode Gates and Rectifiers”. 1. What is the logic gate implemented in the following circuit?

a) OR b) AND c) NOT d) None of the mentioned View Answer Answer: a 1 of 9

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Explanation: In the given circuit, the output is high if either of the inputs is high and hence, it is an OR gate. 2. What is the logic gate implemented in the following circuit?

a) OR b) AND c) NOT d) None of the mentioned View Answer Answer: b Explanation: In the given circuit, the output is high if both of the inputs are high and hence, it is an AND gate. 3. Which of the following statements best describes the reason for not using diodes to implement logic gates? a) Diodes are expensive b) Diodes are unreliable and less efficient c) The diode circuits have limited range of operation d) None of the mentioned View Answer

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Answer: c Explanation: The diode circuits are relatively less stable when compared to the transistor circuits, which are easy to tune in of stability and reliability. 4. In the given circuit, what is the output V0 if E1 = 10V and E2 = 0V?

a) 0 V b) 0.7 V c) 10 V d) 9.3 V View Answer Answer: b Explanation: Here, current through the grounded branch = (10-0.7)/1k=9.3 mA. Hence, voltage drop across the resistor=9.3 V. Hence, V0 =10-9.3V = 0.7 V. 5. In the given circuit, what is the output V0 if E1 = 10V and E2 = 0V?

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a) 0 V b) 0.7 V c) 10 V d) 9.3 V View Answer Answer: d Explanation: V0=10-0.7 V = 9.3 V. 6. A 12 V, 50 Hz sine wave is fed to the given circuit as input? What is the output for 0.01s < t < 0.02s?

a) 12 V, 50 HZ sine wave b) 11.3 V, 25 Hz sine wave c) 0 V d) None of the mentioned View Answer 4 of 9

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Answer: c Explanation: The given circuit is that of a half wave rectifier in which the diode remains in the off state for the negative half cycle and hence, the output for 0.01s <0.02s is zero. 7. Which circuit has been represented in the associated circuit diagram?

a) Half wave rectifier b) Full wave rectifier c) NOT gate d) None of the mentioned View Answer Answer: a Explanation: Both the diodes are similarly biased and are in series. Hence, they form a half wave rectifier. 8. Which circuit has been represented in the associated circuit diagram?

a) Half wave rectifier b) Full wave rectifier c) NOT gate d) None of the mentioned 5 of 9

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View Answer Answer: b Explanation: In the given circuit, when the diode D1 is on, diode D2 is off and vice versa. Hence, the upper diode conducts during the positive half of the input cycle and the lower diode conducts during the negative half of the input cycle and hence, it is a full wave rectifier circuit. 9. What is the value of DC equivalent output voltage for the given circuit, given that the input voltage is 20 Vp-p and 50 Hz and the diode is a silicon diode?

a) 2.9574 V b) -2.9574 V c) -3.125 V d) 0 V View Answer Answer: b Explanation: Vdc is given by 0.318(Vp). Here Vp = 10-0.7 V =9.3 V and hence, Vdc=0.318 x 9.3 V = 2.9574 V. Now, as the output Is non zero only for the negative half cycles of the input, Vdc = -2.9574 V. 10. Which of the following equations is correct for a full wave rectified output?

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a) |Vdc| = 0.318 Vp b) |Vdc| = 0.636 Vp c) |Vdc| = 0.477 Vp d) None of the mentioned View Answer Answer: b Explanation: The output dc level of a half wave rectified wave is equal to 0.318 Vp. But, for a fully rectified wave, it becomes equal to 0.636 of the peak value. 11. Which of the following statements are true about the given circuit?

a) The circuit is that of a bridge rectifier b) The PIV of the diode D1 must be greater than v0 for the circuit to function as a bridge rectifier c) For silicon diodes, the value of v0=(vi-1.4) V d) All of the mentioned View Answer Answer: d Explanation: The circuit is that of a bridge rectifier. For proper functioning, the PIV of diodes must be at least greater than v0 and since, the current through any path 7 of 9

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flows through 2 diodes. There is a drop of 1.4 V. 12. In the given circuit, what will be the nature of the output waveform?

a) Half rectified b) Full rectified c) Sinusoidal d) DC View Answer Answer: b Explanation: The right diode conducts during the positive half of the input cycle and the left diode conducts during the negative half of the input cycle. Hence, the output will be a fully rectified wave. 13. In the given circuit, what is the value of Vp for the output wave, if the input fed is 20 Vp-p?

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a) 10 V b) 9.3 V c) 5 V d) 4.7 V View Answer Answer: c Explanation: As is clear from the circuit that v0 = 0.5 vi and hence peak value of the output wave is equal to half of the peak value of the input wave and hence Vp = 10/2 = 5 V. Sanfoundry Global Education & Learning Series – Analog Circuits. To practice all areas of Analog Circuits, here is complete set of 1000+ Multiple Choice Questions and Answers.

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Diode Basics & Equivalent Circuits Questions a...

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Diode Basics & Equivalent Circuits Questions and Answers by Manish 4-6 minutes

This set of Analog Circuits Multiple Choice Questions & Answers (MCQs) focuses on “Diode Basics and Equivalent Circuits”. 1. Which of the following is not a valid form of a diode equivalent circuit? a) Piecewise Linear Model b) Ideal Diode Model c) Simplified Model d) Differential Model View Answer Answer: d Explanation: Differential model doesn’t define any diode. It defines an Operational Amplifier. 2. Which model of the diode equivalent circuit is represented by the given diagram?

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a) Piecewise Linear Model b) Ideal Diode Model c) Simplified Model d) None of the mentioned View Answer Answer: a Explanation: This model involves a voltage drop and a resistance in series with an ideal diode and hence it represents the Piecewise Linear Model. 3. From the given I-V characteristics of a silicon diode, what is the value of rav between marked points?

a) 5 ohms b) 11.2 ohms c) 8 ohms d) None of the mentioned View Answer Answer: a Explanation: rav. = change in diode voltage per change in 2 of 7

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diode current. Hence, rav = 0.075V/15mA = 5 ohms. 4. AC resistance of a diode was found to be r1 and r2, when measured with two different values of diode current i.e. 10 mA and 25 mA respectively. Which of the following options hold true? a) r1 = r2 b) r1 > r2 c) r1 < r2 d) Can’t be determined. View Answer Answer: b Explanation: r1 > r2 as AC resistance is inversely proportional to the diode current. 5. Which of the following models of diode equivalent circuit is represented by the given I-V characteristic curve?

a) Piecewise Linear Model b) Ideal Diode Model c) Simplified Model d) None of the mentioned View Answer Answer: c Explanation: In simplified model, the value of rd is neglected and hence, we get a high value of current for voltage greater than or equal to VT.

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6. What is the approximate value of voltage across the diode for the diagram given alongside?

a) +0.7 V b) -0.7 V c) +10 V d) -10 V View Answer Answer: d Explanation: -10 V. The operating characteristic of a diode operating in the reverse bias region suggests that beyond a certain threshold current, the voltage across the diode is nearly constant = reverse breakdown voltage. 7. Assuming the diode in the given circuit diagram to be a silicon p-n junction diode, what is the current for the given circuit diagram?

a) 4.3 mA b) 0 c) 43 mA d) 5 mA View Answer Answer: b Explanation: The diode in the circuit is reverse biased and 4 of 7

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hence the current is zero. 8. Assuming the diode in the given circuit diagram to be a silicon p-n junction diode, what is the current for the given circuit diagram?

a) 0 b) 5 mA c) 4.3 mA d) Can’t be determined View Answer Answer: c Explanation: 4.3 mA. The silicon diode in the circuit is forward biased. Considering a voltage drop of 0.7 V across the diode, the voltage drop across the resistor is (5-0.7) V = 4.3 V. Hence, Current in the circuit = Current through the resistor = (4.3/1000) A = 4.3 mA 9. The reverse saturation current for a Germanium diode at a temperature of 293 K is found to be 2 uA. What is the reverse saturation current Is at a temperature of 313 K? a) 2 uA b) 8 uA c) 4 uA d) Can’t be determined View Answer Answer: b Explanation: The reverse saturation current for a silicon

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diode doubles its value for every 10 K rise in temperature. Hence Is at 313 K=2 x 2 x 2 = 8 uA. 10. During the reverse bias operation of a p-n junction diode, the width of the depletion region increases. Is the given statement true or false? a) True b) False View Answer Answer: a Explanation: During reverse bias operation of a diode, the width of the depletion region increases leading to extremely high values of resistance and hence negligible values of current. 11. The threshold voltage of a diode at Antarctica and India were found to be V1 and V2 respectively. Which of the following relations between V1 and V2 hold good? a) V1 > V2 b) V1 = V2 c) V1 < V2 d) Can’t be determined View Answer Answer: a Explanation: Temperature in India is greater than that in Antarctica. Hence, the reverse saturation current measured in India will be higher as compared to that measured in Antarctica. Now, as Is and VT are inversely related, V1 >V2. Sanfoundry Global Education & Learning Series – 6 of 7

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Analog Circuits. To practice all areas of Analog Circuits, here is complete set of 1000+ Multiple Choice Questions and Answers.

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Parallel & Series Configuration - Analog Circuit...

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Parallel & Series Configuration Analog Circuits Questions and Answers by Manish 5-6 minutes

This set of Analog Circuits Multiple Choice Questions & Answers (MCQs) focuses on “Parallel and Series Configuration”. 1. From the given circuit, what is the value of current through the 1 k resistor?

a) 10 mA b) 9.3 mA c) 8.6 mA d) 0 mA View Answer Answer: a

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Explanation: As both the diodes are reverse biased. Voltage drop across the resistor = 10 V. Hence, current = 10 V/1 k = 10 mA. 2. From the given circuit, what is the value of current flowing through the 1 k resistor?

a) 0 mA b) 10 mA c) 9.3 mA d) 0.7 mA View Answer Answer: d Explanation: As one of the diodes is forward biased, voltage drop across it = 0.7 V. Now, as this diode is in parallel with the given resistor, voltage across resistor=0.7 V => current = 0.7 mA. 3. In the given circuit, what is the value of current flowing through the forward biased diode?

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a) 10 mA b) 9.3 mA c) 8.6 mA d) 0 mA View Answer Answer: c Explanation: Here, current flowing through R2 = (10-0.7)/1k = 9.3 mA. Also the current through the parallel resistor=0.7 mA. Hence the current through the forward biased diode = (9.3-0.7) = 8.6 mA. 4. In the given circuit, what is the value of current flowing through the diode D2?

a) 0 mA b) 10 mA c) 9.3 mA d) 8.6 mA 3 of 10

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View Answer Answer: a Explanation: As the diode D2 is reverse biased, current flowing through it = 0 mA. 5. In the given circuit, what is the value of the current through the series resistor R2?

a) 9.3 mA b) 10 mA c) 0 mA d) 8.6 mA View Answer Answer: a Explanation: The voltage across the diodes is 0.7 V as they are forward biased. Hence, the current through the series resistor= (10-0.7)/1k = 9.3 mA. 6. In the given circuit, what is the current through the parallel resistor?

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a) 9.3 mA b) 0.7 mA c) 8.6 mA d) None of the mentioned View Answer Answer: b Explanation: As the resistor is in parallel with the diodes, the voltage that appears across it is 0.7 V. Hence, current = 0.7 mA. 7. In the given circuit, what is the value of current through R?

a) 0.7 mA b) 0.3 mA c) 1 mA d) 10 mA View Answer

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Answer: b Explanation: The source voltage initially increases from 0-10 V. As the source voltage increases, the voltage across the diodes also increases. When the voltage across the diodes reaches a value of 0.3 V, the Germanium diode starts conducting, whereas the silicon diode is still in the off state. Hence, the voltage across R = 0.3 V. Hence, current=0.3 mA. 8. In the given circuit, what is the value of current through R 2?

a) 9.3 mA b) 9.7 mA c) 10 mA d) 0 mA View Answer Answer: b Explanation: Here, the voltage across R=0.3 V, hence, current through R2 = (10-0.3) V/ 1 k = 9.7 mA. 9. In the given circuit, what is the value of current through the silicon diode?

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a) 9.3 mA b) 9.7 mA c) 10 mA d) 0 mA View Answer Answer: d Explanation: The source voltage initially increases from 0-10 V. As the source voltage increases, the voltage across the diodes also increases. When the voltage across the diodes reaches a value of 0.3 V, the Germanium diode starts conducting, whereas the silicon diode is still in the off state. Hence, the voltage across silicon diode = 0.3 V and hence, the current according to the approximate equivalent circuit model is equal to zero. 10. In the given circuit, what is the value of current through the germanium diode?

a) 9.4 mA 7 of 10

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b) 9.7 mA c) 0.3 mA d) 0 mA View Answer Answer: a Explanation: Current through R2 = 9.7 mA. Also, current through R = 0.3 mA, current through the silicon diode=0 mA. Hence, from the KCL, we get the current through the germanium diode to be 9.4 mA. 11. In the given circuit, by what amount does the current across R change when the Germanium diode is reconnected in the reverse-bias mode?

a) 0 mA b) 0.7 mA c) 0.4 mA d) 0.3 mA View Answer Answer: c Explanation: When the germanium diode is forward biased, current through R = 0.3 mA. When the Germanium diode is reverse biased, current through R=0.7 mA. Hence, change in current = 0.4 mA.

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12. In the given circuit, if the diode D2 is a Germanium diode and all other diodes are Silicon diodes, then which of the following statements is true?

a) ID2 > ID3 b) ID2 = ID1 c) Both of the mentioned d) None of the mentioned View Answer Answer: c Explanation: Voltage across the parallel diodes=0.3 V. Hence, current through D3=0. Hence ID2>ID3. Also, as both the parallel silicon diodes are in parallel and in offstate, the diodes 1 and 2 are in series and hence, current through them is same. 13. In the circuit, considering the diode 1,4 to be a Germanium diode and the diodes 2,3 to be silicon, which of the following statements are true?

a) ID1 = ID2

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b) ID1 = ID3 c) ID1 = ID4 d) None of the mentioned View Answer Answer: c Explanation: In the given circuit, the silicon diodes are in off-state as the voltage across them is 0.3 V. Hence, they act as open circuit and the diodes 1 and 4 are in series and hence the current through diodes 1 and 4 is same. Sanfoundry Global Education & Learning Series – Analog Circuits. To practice all areas of Analog Circuits, here is complete set of 1000+ Multiple Choice Questions and Answers.

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Diode Types & its Testing - Analog Circuits Ques...

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Diode Types & its Testing - Analog Circuits Questions and Answers by Manish 6-8 minutes

This set of Analog Circuits Multiple Choice Questions & Answers (MCQs) focuses on “Types of Diode and their Testing”. 1. Which of the following equipment may be used to check the condition of a diode? a) Digital Display Meter b) Ohmmeter c) Curve Tracer d) All of the mentioned View Answer Answer: d Explanation: All the methods may be used to test a diode for its proper functioning. 2. What is the expected reading obtained on a Digital Display Meter with diode-checking function when a proper functioning silicon semiconductor diode is connected across its leads in the forward bias configuration? a) 0.67 V

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b) 0.3 V c) Open Loop Indication d) Varies with the diode View Answer Answer: a Explanation: The diode checking function on the meter when used causes a current of 2 mA to flow through the diode and hence under forward bias, the voltage is determined to be 0.67 V. 3. What is the expected reading obtained on a Digital Display Meter with diode-checking function when a proper functioning silicon semiconductor diode is connected across its leads in the reverse bias configuration? a) 0.67 V b) 0.3 V c) Open Loop Indication d) Varies with the diode View Answer Answer: c Explanation: The diode checking function on the meter when used causes a current of 2 mA to flow through the diode and hence under reverse bias, the result obtained is the open loop indication. 4. A diode on being checked by a DDM with diode checking function results in an open loop indication in both directions. Which of the following is the correct inference drawn from the given situation? a) Power failure to the DDM 2 of 8

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b) Diode is faulty c) Diode is proper d) None of the mentioned View Answer Answer: b Explanation: A diode allows electrical conduction in just one direction. Hence, if an instrument shows open loop indication in both the directions, then the diode is faulty. 5. A silicon semiconductor diode when subjected to ohmmeter testing gives low resistance in both the directions. Which of the following is the correct inference to be drawn? a) Diode is faulty b) Power failure to the Ohmmeter c) Diode is short-circuited d) Can’t be determined View Answer Answer: c Explanation: A proper diode gives a low resistance reading along one direction and high resistance reading along the other. Hence, if diode gives low resistance readings in both the directions, then the diode must be short-circuited. It’s noteworthy that a faulty diode gives a high resistance reading along both the paths. 6. A silicon semiconductor diode when subjected to ohmmeter testing gives high resistance in both the directions. Which of the following is the correct inference to be drawn? 3 of 8

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Diode Types & its Testing - Analog Circuits Ques...

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a) Diode is faulty b) Power failure to the Ohmmeter c) Diode is short-circuited d) Can’t be determined View Answer Answer: a Explanation: A proper diode gives a low resistance reading along one direction and high resistance reading along the other. Hence, if diode gives high resistance readings in both the directions, then the diode must be faulty. 7. How can the location of the Zener region be controlled in the diode characteristic curve? a) By changing the value of Iz b) By changing the doping concentration of the diode c) By changing the operating temperature d) Can’t be changed View Answer Answer: b Explanation: An increase in doping will lead to an increase in the concentration of impurities, which would further lead to a change in VZ and hence change in the Zener region. 8. Which material is generally used for the manufacture of Zener diode? a) Silicon b) Germanium c) Mercury d) None of the mentioned View Answer 4 of 8

3/16/18, 4:07 PM

Diode Types & its Testing - Analog Circuits Ques...

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Answer: a Explanation: Because of its high heat and current handling capacity, Silicon is generally used for the manufacture of Zener diodes. 9. Which of the following is not a part of the equivalent circuit of a Zener diode? a) Dynamic Resistance b) DC Battery c) Ideal diode d) None of the mentioned View Answer Answer: c Explanation: The equivalent circuit diagram of a Zener diode doesn’t involve an ideal diode as it is used under reverse bias and an ideal diode doesn’t conduct under reverse bias. 10. At 298 K, the nominal Zener voltage is found to be equal to 10 V. Given that the value of Temperature coefficient is 0.072 (%/K), what is the nominal Zener Voltage at 398 K? a) 9.46 V b) 9.54 V c) 0.54 V d) 10.54 V View Answer Answer: d Explanation: The change in VZ with temperature is calculated from the following equation: 5 of 8

3/16/18, 4:07 PM

Diode Types & its Testing - Analog Circuits Ques...

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Change in VZ = TC.VZ(T1 – T0))/1000 Change in VZ = 0.54 V Now, as the value of T ¬is positive, new VZ = 10 + 0.54 V = 10.54 V 11. Which of the following materials is used to make LEDs? a) Silicon b) GaAsP c) Germanium d) All of the mentioned View Answer Answer: b Explanation: In Silicon and Germanium, the major chunk of energy is given off as heat the hence the emitted light isn’t significant. In Gallium Arsenide Phosphide (GaAsP), the number of photons are enough to create a visual source of light. 12. Which of the following voltages may be considered as a safe and sufficient voltage for the operation of a LED? a) 0.7 V b) 5 V c) 2.7 V d) -5 V View Answer Answer: c Explanation: The safe and sufficient operating voltage range for LED is between 1.7 V to 3.3 V. Hence, 2.7 V is the best option. 13. What is the order of magnitude of the response time of 6 of 8

3/16/18, 4:07 PM

Diode Types & its Testing - Analog Circuits Ques...

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LED? a) 10-6 b) 10-9 c) 10-15 d) 10-3 View Answer Answer: b Explanation: The response time of a LED is typically in the order of nanoseconds. 14. Which of the following is an advantage of using a LED? a) Low response time b) Compatibility with solid-state circuits c) Rugged construction and high lifetime d) All of the mentioned View Answer Answer: d Explanation: The response time of a LED is typically in the order of nanoseconds. The operating voltage range for LED is between 1.7 V to 3.3 V which makes it compatible with solid-state circuits. Also, the semiconductor construction makes them rugged. 15. A LED will glow, if connected under reverse bias configuration: a) True b) False View Answer Answer: b Explanation: A Light Emitting Diode works just like any 7 of 8

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Diode Types & its Testing - Analog Circuits Ques...

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other diode and hence it does not conduct under reverse bias operation and hence the LED will not glow. Sanfoundry Global Education & Learning Series – Analog Circuits. To practice all areas of Analog Circuits, here is complete set of 1000+ Multiple Choice Questions and Answers.

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