All Exams > Electronics and Communication Engineering (ECE) > Analog Circuits > MCQ Questions
Diode Circuits MCQs for Electronics and Communication Engineering (ECE) Exam
It covers all Important Questions with answers on Diode Circuits for the Electronics and Communication Engineering (ECE) exam. The questions are based on important topics. Details about the questions:- Topic: Diode Circuits
- Type of Questions: MCQs with solutions
- Number of Questions: 34
- You can attempt them on EduRev to score high in Electronics and Communication Engineering (ECE) exam.
In the question a circuit and a waveform for the input voltage is given. The diode in circuit has cutin voltage Vγ = 0. Choose the option for the waveform of output voltage vo 
- a)
- b)
- c)
- d)
Correct answer is option 'D'. Can you explain this answer?
In the question a circuit and a waveform for the input voltage is given. The diode in circuit has cutin voltage Vγ = 0. Choose the option for the waveform of output voltage vo
a)
b)
c)
d)
 | Ankit Mukherjee answered |
Diode is off for vi < 5 V. Hence vo = 5 V.
For vi > 5 V, vo = vi .Therefore (D) is correct option.
The secondary transformer voltage of the rectifier circuit shown in fig. is vs = 60 sin 2π 60tV. Each diode has a cut in voltage of Vγ = 0.6 V. The ripple voltage is to be no more than Vrip = 2 V. The value of filter capacitor will be
- a)48.8 μF
- b)24.4 μF
- c)32.2 μF
- d)16.1 μF
Correct answer is option 'B'. Can you explain this answer?
The secondary transformer voltage of the rectifier circuit shown in fig. is vs = 60 sin 2π 60tV. Each diode has a cut in voltage of Vγ = 0.6 V. The ripple voltage is to be no more than Vrip = 2 V. The value of filter capacitor will be
a)
48.8 μF
b)
24.4 μF
c)
32.2 μF
d)
16.1 μF
 | Zoya Sharma answered |
vs = 60 sin 2π 60tV
A half wave rectifier is used to supply 24 V DC to a resistive load of 500 Ω and the diode has a forward resistance of 50 Ω. What is the maximum value of the AC voltage required at the input?- a)82.94 V
- b)66.67 V
- c)94.80 V
- d)none of these
Correct answer is option 'A'. Can you explain this answer?
A half wave rectifier is used to supply 24 V DC to a resistive load of 500 Ω and the diode has a forward resistance of 50 Ω. What is the maximum value of the AC voltage required at the input?
a)
82.94 V
b)
66.67 V
c)
94.80 V
d)
none of these
 | Sushant Mukherjee answered |
Average value of load current,
Maximum value of load current,
Therefore, maximum AC voltage required at the input is
Maximum value of load current,
Therefore, maximum AC voltage required at the input is
The Q-point for the Zener diode in fig. is
- a)(0.34 mA, 4 V)
- b)(0.34 mA, 4.93 V)
- c)(0.94 mA, 4 V)
- d)(0.94 mA, 4.93 V)
Correct answer is option 'A'. Can you explain this answer?
The Q-point for the Zener diode in fig. is
a)
(0.34 mA, 4 V)
b)
(0.34 mA, 4.93 V)
c)
(0.94 mA, 4 V)
d)
(0.94 mA, 4.93 V)
 | Suraj S answered |
Terminal voltage of zener is always its reverse breakdown voltage, and current is equal to the external resistor current
Assertion (A): Bridge arrangement is preferred over centre-tapped transformer arrangement for full-wave rectification.
Reason (R): The bridge arrangement improves the filtering action.- a)Both A and R are true and R is the correct explanation of A.
- b)Both A and R are true but R is not the correct explanation of A.
- c)A is true but R is false.
- d)A is faise but R is true.
Correct answer is option 'C'. Can you explain this answer?
Assertion (A): Bridge arrangement is preferred over centre-tapped transformer arrangement for full-wave rectification.
Reason (R): The bridge arrangement improves the filtering action.
Reason (R): The bridge arrangement improves the filtering action.
a)
Both A and R are true and R is the correct explanation of A.
b)
Both A and R are true but R is not the correct explanation of A.
c)
A is true but R is false.
d)
A is faise but R is true.
 | Pallavi Nair answered |
No filtering action is provided by bridge arrangement. Hence, reason is a false statement.
Which of the following is not a necessary component in a clamper circuit?- a)Diode
- b)Capacitor
- c)Resistor
- d)Independent DC Supply
Correct answer is option 'D'. Can you explain this answer?
Which of the following is not a necessary component in a clamper circuit?
a)
Diode
b)
Capacitor
c)
Resistor
d)
Independent DC Supply
 | Tanya Chauhan answered |
In a clamper circuit, the primary purpose is to shift the DC level of the input signal without altering the shape of the signal. This is achieved by adding a DC bias to the input signal. The necessary components in a clamper circuit include a diode, a capacitor, and a resistor.
- Diode: The diode is an essential component in a clamper circuit as it allows the flow of current in one direction while blocking it in the opposite direction. It helps in shifting the DC level of the input signal by allowing the capacitor to charge or discharge through it.
- Capacitor: The capacitor is another necessary component in a clamper circuit. It is connected in parallel to the diode and is charged or discharged depending on the input signal. The capacitor stores the charge and releases it during the negative half-cycle of the input signal, thereby shifting the DC level of the signal.
- Resistor: The resistor is also an important component in a clamper circuit. It is connected in series with the diode and capacitor. The resistor limits the current flowing through the circuit and helps in stabilizing the voltage across the capacitor.
- Independent DC Supply: The independent DC supply is not a necessary component in a clamper circuit. It is not required because the purpose of a clamper circuit is to shift the DC level of the input signal using the existing components. The diode, capacitor, and resistor work together to achieve this without the need for an additional DC supply.
Therefore, the correct answer is option 'D' - Independent DC Supply.
- Diode: The diode is an essential component in a clamper circuit as it allows the flow of current in one direction while blocking it in the opposite direction. It helps in shifting the DC level of the input signal by allowing the capacitor to charge or discharge through it.
- Capacitor: The capacitor is another necessary component in a clamper circuit. It is connected in parallel to the diode and is charged or discharged depending on the input signal. The capacitor stores the charge and releases it during the negative half-cycle of the input signal, thereby shifting the DC level of the signal.
- Resistor: The resistor is also an important component in a clamper circuit. It is connected in series with the diode and capacitor. The resistor limits the current flowing through the circuit and helps in stabilizing the voltage across the capacitor.
- Independent DC Supply: The independent DC supply is not a necessary component in a clamper circuit. It is not required because the purpose of a clamper circuit is to shift the DC level of the input signal using the existing components. The diode, capacitor, and resistor work together to achieve this without the need for an additional DC supply.
Therefore, the correct answer is option 'D' - Independent DC Supply.
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
Correct answer is option 'C'. Can you explain this answer?
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
| | Ankit Mukherjee answered |
It is not possible to determine the value of vi at which the clipping begins without additional information about the circuit. The clipping voltage depends on the specific characteristics and parameters of the circuit, such as the diode threshold voltage or the supply voltage.
What is the value of inductance to be used in the inductor filter connected to a full-wave rectifier operation at 60 Hz to provide a DC output with 4% ripple for a 100 Ω load?- a)0.88 H
- b)1.25H
- c)1.34 H
- d)1.56 H
Correct answer is option 'D'. Can you explain this answer?
What is the value of inductance to be used in the inductor filter connected to a full-wave rectifier operation at 60 Hz to provide a DC output with 4% ripple for a 100 Ω load?
a)
0.88 H
b)
1.25H
c)
1.34 H
d)
1.56 H
| | Debanshi Nair answered |
The ripple factor for an inductor filter is
∴
or
∴
or
The value of power dissipated across the Zener diode (Vz=15 V) connected in the circuit as shown in the figure is x × 10−1 watts.
The value of x to the nearest integer is- a)2
- b)4.5
- c)6
- d)5
Correct answer is option 'D'. Can you explain this answer?
The value of power dissipated across the Zener diode (Vz=15 V) connected in the circuit as shown in the figure is x × 10−1 watts.
The value of x to the nearest integer is
The value of x to the nearest integer is
a)
2
b)
4.5
c)
6
d)
5
 | EduRev GATE answered |
Across R1, potential difference is 22 V−15 V = 7 V
In the question a circuit and a waveform for the input voltage is given. The diode in circuit has cutin voltage Vγ = 0. Choose the option for the waveform of output voltage vo 
- a)
- b)
- c)
- d)
Correct answer is option 'C'. Can you explain this answer?
In the question a circuit and a waveform for the input voltage is given. The diode in circuit has cutin voltage Vγ = 0. Choose the option for the waveform of output voltage vo
a)
b)
c)
d)
 | Mira Sharma answered |
During positive cycle when vs < 8V both diode are OFF vo = vs . For vs > 8V , vo = 8V , D1 is ON.During
negative cycle when |vs| < 6 V, both diode are OFF, vo = vs . For |vs| > 6V , D2 is on v0 = -6V .Therefore (C) is
correct.
negative cycle when |vs| < 6 V, both diode are OFF, vo = vs . For |vs| > 6V , D2 is on v0 = -6V .Therefore (C) is
correct.
What is the circuit in the given diagram called?
- a)Clipper
- b)Clamper
- c)Half wave rectifier
- d)Full wave rectifier
Correct answer is option 'B'. Can you explain this answer?
What is the circuit in the given diagram called?
a)
Clipper
b)
Clamper
c)
Half wave rectifier
d)
Full wave rectifier
 | Sarita Yadav answered |
During the positive half cycle, the diode is forward biased and no signal appears across the output. The capacitor holds the charge in that state. During negative cycle, diode is reverse biased and diode does not conduct. The charge in capacitor is released and is obtained at the output.
Assertion (A): A high value of resistor is connected across the diode in a clamper circuit for better performance.
Reason (R): If this resistor is not present, the circuit will respond to sudden decrease in the magnitude of the input pulse train, but the response to sudden increase in the amplitude will cause improper response.- a)Both A and R are true and R is the correct explanation of A.
- b)Both A and R are true but R is not the correct explanation of A.
- c)A is true but R is false.
- d)A is false but R is true.
Correct answer is option 'A'. Can you explain this answer?
Assertion (A): A high value of resistor is connected across the diode in a clamper circuit for better performance.
Reason (R): If this resistor is not present, the circuit will respond to sudden decrease in the magnitude of the input pulse train, but the response to sudden increase in the amplitude will cause improper response.
Reason (R): If this resistor is not present, the circuit will respond to sudden decrease in the magnitude of the input pulse train, but the response to sudden increase in the amplitude will cause improper response.
a)
Both A and R are true and R is the correct explanation of A.
b)
Both A and R are true but R is not the correct explanation of A.
c)
A is true but R is false.
d)
A is false but R is true.
 | Sneha Nair answered |
Assertion (A): A high value of resistor is connected across the diode in a clamper circuit for better performance.
Reason (R): If this resistor is not present, the circuit will respond to sudden decrease in the magnitude of the input pulse train, but the response to sudden increase in the amplitude will cause improper response.
Explanation:
Clamper circuits are used to shift the DC level of a waveform. They are commonly used in applications such as video signal processing, where it is necessary to shift the DC level of the video signal to a desired level.
Working of a Clamper Circuit:
A clamper circuit consists of a diode, a capacitor, and a resistor. The diode is typically connected in series with the capacitor and the resistor is connected across the diode. The input waveform is applied across the series combination of the diode and the capacitor.
When the input waveform is positive, the diode is forward-biased and charges the capacitor to the peak value of the positive input waveform. The voltage across the capacitor is then added to the input waveform, shifting the DC level of the waveform. When the input waveform is negative, the diode is reverse-biased and the capacitor retains its charge, resulting in the shifting of the DC level.
Role of the Resistor:
The resistor connected across the diode in a clamper circuit serves multiple purposes:
1. Discharge Path: The resistor provides a discharge path for the capacitor when the input waveform is negative. This ensures that the capacitor is discharged properly before the next positive cycle of the input waveform.
2. Protective Role: The resistor limits the current flowing through the diode, preventing it from getting damaged due to excessive current. It acts as a protective element.
3. Proper Response: The high value of the resistor ensures that the circuit responds properly to sudden increases in the amplitude of the input pulse train. If the resistor is not present or has a low value, the sudden increase in amplitude may cause improper response or distortion in the output waveform.
Therefore, both the assertion (A) and the reason (R) are true, and the reason (R) provides the correct explanation for the assertion (A). The presence of a high-value resistor across the diode in a clamper circuit is essential for better performance and proper response to input waveforms.
Reason (R): If this resistor is not present, the circuit will respond to sudden decrease in the magnitude of the input pulse train, but the response to sudden increase in the amplitude will cause improper response.
Explanation:
Clamper circuits are used to shift the DC level of a waveform. They are commonly used in applications such as video signal processing, where it is necessary to shift the DC level of the video signal to a desired level.
Working of a Clamper Circuit:
A clamper circuit consists of a diode, a capacitor, and a resistor. The diode is typically connected in series with the capacitor and the resistor is connected across the diode. The input waveform is applied across the series combination of the diode and the capacitor.
When the input waveform is positive, the diode is forward-biased and charges the capacitor to the peak value of the positive input waveform. The voltage across the capacitor is then added to the input waveform, shifting the DC level of the waveform. When the input waveform is negative, the diode is reverse-biased and the capacitor retains its charge, resulting in the shifting of the DC level.
Role of the Resistor:
The resistor connected across the diode in a clamper circuit serves multiple purposes:
1. Discharge Path: The resistor provides a discharge path for the capacitor when the input waveform is negative. This ensures that the capacitor is discharged properly before the next positive cycle of the input waveform.
2. Protective Role: The resistor limits the current flowing through the diode, preventing it from getting damaged due to excessive current. It acts as a protective element.
3. Proper Response: The high value of the resistor ensures that the circuit responds properly to sudden increases in the amplitude of the input pulse train. If the resistor is not present or has a low value, the sudden increase in amplitude may cause improper response or distortion in the output waveform.
Therefore, both the assertion (A) and the reason (R) are true, and the reason (R) provides the correct explanation for the assertion (A). The presence of a high-value resistor across the diode in a clamper circuit is essential for better performance and proper response to input waveforms.
For the given circuit, what is the minimum peak value of the output waveform if the input waveform is 10V square 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
Correct answer is option 'C'. Can you explain this answer?
For the given circuit, what is the minimum peak value of the output waveform if the input waveform is 10V square wave with switching time of 1 second?
Assume that the input switches between +10V and -10V DC levels.
Assume that the input switches between +10V and -10V DC levels.
a)
0 V
b)
-5 V
c)
-20 V
d)
-10 V
| | Sarita Yadav answered |
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.
When a capacitor is connected across the output terminals of a half or full-wave rectifier, the output voltage- a)essentially becomes a DC voltage.
- b)becomes sinusoidal with a phase lag of 90 degrees.
- c)exhibits sharp spikes.
- d)is shifted up or down by the amplitude of the incoming sinusoid.
Correct answer is option 'A'. Can you explain this answer?
When a capacitor is connected across the output terminals of a half or full-wave rectifier, the output voltage
a)
essentially becomes a DC voltage.
b)
becomes sinusoidal with a phase lag of 90 degrees.
c)
exhibits sharp spikes.
d)
is shifted up or down by the amplitude of the incoming sinusoid.
 | Palak Patel answered |
Explanation:
When a capacitor is connected across the output terminals of a half or full-wave rectifier, the output voltage essentially becomes a DC voltage.
Rectification:
Rectification is the process of converting an alternating current (AC) into a direct current (DC). A rectifier is used to perform this conversion. Half-wave and full-wave rectifiers are commonly used rectification circuits.
Half-wave rectifier:
In a half-wave rectifier, only one half of the input AC waveform is utilized. The diode in the circuit allows the positive half of the input AC waveform to pass through, while blocking the negative half. As a result, the output waveform consists of only the positive half of the input waveform.
Full-wave rectifier:
In a full-wave rectifier, both halves of the input AC waveform are utilized. The circuit uses a combination of diodes to allow both the positive and negative halves of the input waveform to pass through. This results in a full-wave rectified output waveform.
Output voltage:
The output voltage of a rectifier without a capacitor connected across the output terminals is a pulsating DC voltage. This voltage varies in amplitude but does not have a constant value. It consists of a series of positive pulses for a half-wave rectifier and a series of positive and negative pulses for a full-wave rectifier.
Effect of capacitor:
When a capacitor is connected across the output terminals of a rectifier, it acts as a filter. It smoothens the pulsating DC voltage and converts it into a more stable DC voltage.
Charging and discharging of capacitor:
During the positive half-cycle of the rectified waveform, the capacitor charges up to the peak voltage of the rectified waveform. During the negative half-cycle, the capacitor discharges through the load. This charging and discharging process results in a more continuous and stable DC voltage across the load.
Effect of capacitor on output voltage:
The presence of the capacitor across the output terminals of the rectifier eliminates the pulsations and fluctuations in the output voltage. The capacitor holds a charge during the charging phase and discharges slowly during the discharging phase, maintaining a relatively constant voltage across the load.
DC voltage:
As a result, the output voltage essentially becomes a DC voltage. Although there may be some ripple voltage (small AC component) remaining due to the capacitor's charging and discharging cycle, it is significantly reduced compared to the rectified voltage without the capacitor. The remaining ripple can be further minimized by increasing the capacitance value of the capacitor.
Therefore, the correct answer is option 'A': The output voltage essentially becomes a DC voltage.
When a capacitor is connected across the output terminals of a half or full-wave rectifier, the output voltage essentially becomes a DC voltage.
Rectification:
Rectification is the process of converting an alternating current (AC) into a direct current (DC). A rectifier is used to perform this conversion. Half-wave and full-wave rectifiers are commonly used rectification circuits.
Half-wave rectifier:
In a half-wave rectifier, only one half of the input AC waveform is utilized. The diode in the circuit allows the positive half of the input AC waveform to pass through, while blocking the negative half. As a result, the output waveform consists of only the positive half of the input waveform.
Full-wave rectifier:
In a full-wave rectifier, both halves of the input AC waveform are utilized. The circuit uses a combination of diodes to allow both the positive and negative halves of the input waveform to pass through. This results in a full-wave rectified output waveform.
Output voltage:
The output voltage of a rectifier without a capacitor connected across the output terminals is a pulsating DC voltage. This voltage varies in amplitude but does not have a constant value. It consists of a series of positive pulses for a half-wave rectifier and a series of positive and negative pulses for a full-wave rectifier.
Effect of capacitor:
When a capacitor is connected across the output terminals of a rectifier, it acts as a filter. It smoothens the pulsating DC voltage and converts it into a more stable DC voltage.
Charging and discharging of capacitor:
During the positive half-cycle of the rectified waveform, the capacitor charges up to the peak voltage of the rectified waveform. During the negative half-cycle, the capacitor discharges through the load. This charging and discharging process results in a more continuous and stable DC voltage across the load.
Effect of capacitor on output voltage:
The presence of the capacitor across the output terminals of the rectifier eliminates the pulsations and fluctuations in the output voltage. The capacitor holds a charge during the charging phase and discharges slowly during the discharging phase, maintaining a relatively constant voltage across the load.
DC voltage:
As a result, the output voltage essentially becomes a DC voltage. Although there may be some ripple voltage (small AC component) remaining due to the capacitor's charging and discharging cycle, it is significantly reduced compared to the rectified voltage without the capacitor. The remaining ripple can be further minimized by increasing the capacitance value of the capacitor.
Therefore, the correct answer is option 'A': The output voltage essentially becomes a DC voltage.
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
- d)0 V
Correct answer is option 'D'. Can you explain this answer?
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
d)
0 V
 | Ravi Singh answered |
The given circuit is a clipper that 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.
In the question a circuit and a waveform for the input voltage is given. The diode in circuit has cutin voltage Vγ = 0. Choose the option for the waveform of output voltage vo 
- a)
- b)
- c)
- d)
Correct answer is option 'D'. Can you explain this answer?
In the question a circuit and a waveform for the input voltage is given. The diode in circuit has cutin voltage Vγ = 0. Choose the option for the waveform of output voltage vo
a)
b)
c)
d)
 | Diya Chopra answered |
For vi < 4 V the diode is ON and output vo = 4 V.
For vi >4 V diode is off and output vo = vi.
Thus (D) is correct option.
Thus (D) is correct option.
Chapter doubts & questions for Diode Circuits - Analog Circuits 2026 is part of Electronics and Communication Engineering (ECE) exam preparation. The chapters have been prepared according to the Electronics and Communication Engineering (ECE) exam syllabus. The Chapter doubts & questions, notes, tests & MCQs are made for Electronics and Communication Engineering (ECE) 2026 Exam. Find important definitions, questions, notes, meanings, examples, exercises, MCQs and online tests here.
Chapter doubts & questions of Diode Circuits - Analog Circuits in English & Hindi are available as part of Electronics and Communication Engineering (ECE) exam. Download more important topics, notes, lectures and mock test series for Electronics and Communication Engineering (ECE) Exam by signing up for free.
Analog Circuits3 videos|90 docs|64 tests |
