1. What is the primary function of a Varistor diode?
A. To rectify AC b) To limit the voltage to a safe level c) To amplify
weak signals d) To emit light
Answer: b) To limit the voltage to a safe level Rationale: Varistors are
used to protect circuits from voltage spikes by limiting the voltage to a
safe level when the voltage exceeds a certain threshold.
2. In a full-wave rectifier, how many diodes are typically used?
A. One b) Two c) Four d) Six
Answer: c) Four Rationale: A full-wave rectifier typically uses four
diodes arranged in a bridge configuration to convert the entire AC
waveform to DC.
3. A diode is used in a circuit with a reverse bias voltage of 12V. If the
diode is a Zener diode with a breakdown voltage of 6V, what will
happen?
A. The diode will be damaged b) The diode will conduct in reverse bias
and maintain a voltage of 6V c) The diode will block current flow d)
The diode will conduct with a forward voltage drop of 0.7V
Answer: b) The diode will conduct in reverse bias and maintain a
voltage of 6V Rationale: A Zener diode in reverse bias will conduct and
maintain a constant voltage equal to its breakdown voltage (6V), even if
the reverse voltage exceeds that value.
,4. What is the typical application of a Light Emitting Diode (LED)?
A. Signal amplification b) Voltage regulation
C. Display and indicator lights d) Power rectification
Answer: c) Display and indicator lights Rationale: LEDs are used for
displays, indicators, and other light-emitting applications due to their
ability to emit light when current flows through them in the forward
direction.
5. What type of diode is used for high-frequency microwave
applications?
A. Zener diode b) Schottky diode c) Tunnel diode d) Light Emitting
Diode (LED)
Answer: c) Tunnel diode Rationale: Tunnel diodes are used in high-
frequency microwave applications due to their ability to operate at very
high speeds.
6. In which of the following cases does a diode behave like an open
circuit?
A. Forward biased with high current b) Reverse biased with voltage
less than the breakdown voltage c) Forward biased with low voltage d)
Reverse biased with voltage greater than the breakdown voltage
Answer: b) Reverse biased with voltage less than the breakdown
voltage Rationale: In reverse bias, a diode behaves like an open circuit
, when the reverse voltage is below the breakdown voltage, meaning no
current flows.
7. What is the primary reason for using a diode in a circuit?
A. To store energy b) To allow current to flow in both directions c) To
provide a path for current in one direction only d) To amplify signals
Answer: c) To provide a path for current in one direction only
Rationale: Diodes are used to control the direction of current flow,
allowing current to pass in one direction and blocking it in the opposite
direction.
8. What is the difference between a P-N junction diode and a Schottky
diode?
A. Schottky diodes have a metal-semiconductor junction, while P-N
diodes have a semiconductor-semiconductor junction b) Schottky
diodes can conduct in both directions, while P-N diodes can conduct in
one direction only c) P-N diodes are used for high-speed applications,
while Schottky diodes are not d) Schottky diodes have a higher forward
voltage drop compared to P-N diodes
Answer: a) Schottky diodes have a metal-semiconductor junction, while
P-N diodes have a semiconductor-semiconductor junction Rationale:
Schottky diodes use a metal-semiconductor junction, which results in a
lower forward voltage drop and faster switching speeds compared to
traditional P-N junction diodes.
A. To rectify AC b) To limit the voltage to a safe level c) To amplify
weak signals d) To emit light
Answer: b) To limit the voltage to a safe level Rationale: Varistors are
used to protect circuits from voltage spikes by limiting the voltage to a
safe level when the voltage exceeds a certain threshold.
2. In a full-wave rectifier, how many diodes are typically used?
A. One b) Two c) Four d) Six
Answer: c) Four Rationale: A full-wave rectifier typically uses four
diodes arranged in a bridge configuration to convert the entire AC
waveform to DC.
3. A diode is used in a circuit with a reverse bias voltage of 12V. If the
diode is a Zener diode with a breakdown voltage of 6V, what will
happen?
A. The diode will be damaged b) The diode will conduct in reverse bias
and maintain a voltage of 6V c) The diode will block current flow d)
The diode will conduct with a forward voltage drop of 0.7V
Answer: b) The diode will conduct in reverse bias and maintain a
voltage of 6V Rationale: A Zener diode in reverse bias will conduct and
maintain a constant voltage equal to its breakdown voltage (6V), even if
the reverse voltage exceeds that value.
,4. What is the typical application of a Light Emitting Diode (LED)?
A. Signal amplification b) Voltage regulation
C. Display and indicator lights d) Power rectification
Answer: c) Display and indicator lights Rationale: LEDs are used for
displays, indicators, and other light-emitting applications due to their
ability to emit light when current flows through them in the forward
direction.
5. What type of diode is used for high-frequency microwave
applications?
A. Zener diode b) Schottky diode c) Tunnel diode d) Light Emitting
Diode (LED)
Answer: c) Tunnel diode Rationale: Tunnel diodes are used in high-
frequency microwave applications due to their ability to operate at very
high speeds.
6. In which of the following cases does a diode behave like an open
circuit?
A. Forward biased with high current b) Reverse biased with voltage
less than the breakdown voltage c) Forward biased with low voltage d)
Reverse biased with voltage greater than the breakdown voltage
Answer: b) Reverse biased with voltage less than the breakdown
voltage Rationale: In reverse bias, a diode behaves like an open circuit
, when the reverse voltage is below the breakdown voltage, meaning no
current flows.
7. What is the primary reason for using a diode in a circuit?
A. To store energy b) To allow current to flow in both directions c) To
provide a path for current in one direction only d) To amplify signals
Answer: c) To provide a path for current in one direction only
Rationale: Diodes are used to control the direction of current flow,
allowing current to pass in one direction and blocking it in the opposite
direction.
8. What is the difference between a P-N junction diode and a Schottky
diode?
A. Schottky diodes have a metal-semiconductor junction, while P-N
diodes have a semiconductor-semiconductor junction b) Schottky
diodes can conduct in both directions, while P-N diodes can conduct in
one direction only c) P-N diodes are used for high-speed applications,
while Schottky diodes are not d) Schottky diodes have a higher forward
voltage drop compared to P-N diodes
Answer: a) Schottky diodes have a metal-semiconductor junction, while
P-N diodes have a semiconductor-semiconductor junction Rationale:
Schottky diodes use a metal-semiconductor junction, which results in a
lower forward voltage drop and faster switching speeds compared to
traditional P-N junction diodes.
