426️⃣
Q: A circuit that removes a portion of an input signal without distorting the remaining part is called a
Options:
A) Clamper
B) Rectifier
C) Clipper
D) Multiplier
Answer: C) Clipper
Explanation:
A clipper circuit “clips” part of the waveform beyond a preset level without altering the remaining waveform.
427️⃣
Q: A clamper circuit is used to
Options:
A) Shift the DC level
B) Amplify signal
C) Filter AC component
D) Reduce noise
Answer: A) Shift the DC level
Explanation:
Clampers add or subtract a DC component, moving the signal up or down on the voltage axis.
428️⃣
Q: A positive clipper removes
Options:
A) Negative half cycles
B) Positive half cycles
C) Both halves
D) None
Answer: B) Positive half cycles
Explanation:
A positive clipper clips or removes the positive peaks of the waveform.
429️⃣
Q: A negative clipper removes
Options:
A) Negative portion of signal
B) Positive portion of signal
C) Both
D) None
Answer: A) Negative portion of signal
Explanation:
Negative clippers remove the negative half cycles of the waveform.
430️⃣
Q: The component that stores charge in a clamper circuit is
Options:
A) Diode
B) Resistor
C) Capacitor
D) Inductor
Answer: C) Capacitor
Explanation:
Clampers use a capacitor to shift the DC level of a waveform by storing and releasing charge.
431️⃣
Q: In a clamper, the diode conducts during
Options:
A) Positive half cycle
B) Negative half cycle
C) Both half cycles
D) None
Answer: B) Negative half cycle
Explanation:
The diode conducts when the input drives the capacitor to store charge (typically during negative half).
432️⃣
Q: A biased clipper allows
Options:
A) Clipping at any desired level
B) Only zero-level clipping
C) Amplification
D) Wave shaping
Answer: A) Clipping at any desired level
Explanation:
By adding a DC source, clipping level can be set to a specific voltage other than zero.
433️⃣
Q: In a clamper circuit, when the diode is ideal, the output voltage is
Options:
A) Same as input
B) Shifted version of input
C) Half of input
D) Inverted
Answer: B) Shifted version of input
Explanation:
Clamper circuits shift the waveform vertically without changing its shape.
434️⃣
Q: Which combination forms a positive clamper?
Options:
A) Diode–capacitor
B) Diode–resistor
C) Diode–inductor
D) Resistor–capacitor only
Answer: A) Diode–capacitor
Explanation:
Positive clamper adds positive DC bias using a diode and capacitor.
435️⃣
Q: The time constant of an RC clamper must be
Options:
A) Very small
B) Very large
C) Equal to one cycle
D) Zero
Answer: B) Very large
Explanation:
A large time constant ensures the capacitor voltage remains nearly constant over one cycle.
436️⃣
Q: A photodiode works in which bias?
Options:
A) Forward bias
B) Reverse bias
C) Zero bias
D) Both
Answer: B) Reverse bias
Explanation:
Photodiodes are reverse biased to allow light-generated current proportional to light intensity.
437️⃣
Q: In a photodiode, the reverse current is
Options:
A) Independent of light
B) Increases with light intensity
C) Decreases with light
D) Zero
Answer: B) Increases with light intensity
Explanation:
Light photons generate additional carriers, increasing the reverse current.
438️⃣
Q: A photodiode is used in
Options:
A) Voltage regulation
B) Light detection
C) Oscillators
D) Modulators
Answer: B) Light detection
Explanation:
Photodiodes convert light intensity into electrical current and are used in sensors and optical receivers.
439️⃣
Q: The semiconductor commonly used in LEDs is
Options:
A) Si
B) Ge
C) GaAs
D) Cu
Answer: C) GaAs
Explanation:
Gallium Arsenide (and related compounds) emit visible or infrared light efficiently.
440️⃣
Q: The color of LED light depends on
Options:
A) Doping level
B) Bandgap energy
C) Forward current
D) Reverse voltage
Answer: B) Bandgap energy
Explanation:
Light color corresponds to the photon energy, which equals the semiconductor bandgap energy.
441️⃣
Q: A typical forward voltage drop across an LED is
Options:
A) 0.3 V
B) 0.7 V
C) 1.2–3.5 V
D) 5 V
Answer: C) 1.2–3.5 V
Explanation:
LEDs have higher forward drops depending on color (material bandgap).
442️⃣
Q: The efficiency of an LED improves by
Options:
A) Increasing temperature
B) Using direct bandgap materials
C) Reducing forward current
D) Using indirect bandgap materials
Answer: B) Using direct bandgap materials
Explanation:
Direct bandgap semiconductors emit photons efficiently during recombination.
443️⃣
Q: The LASER diode operates based on
Options:
A) Spontaneous emission
B) Stimulated emission
C) Avalanche emission
D) Thermal emission
Answer: B) Stimulated emission
Explanation:
LASER diodes amplify light by stimulated emission of photons.
444️⃣
Q: The PIN diode consists of
Options:
A) P–N junction only
B) P–I–N layers
C) N–P–N layers
D) P–N–P layers
Answer: B) P–I–N layers
Explanation:
A PIN diode has an intrinsic layer between P and N regions, increasing depletion width.
445️⃣
Q: The intrinsic region in PIN diode provides
Options:
A) High capacitance
B) Low capacitance and high breakdown
C) Forward resistance
D) Reverse leakage
Answer: B) Low capacitance and high breakdown
Explanation:
The wide intrinsic region reduces capacitance and allows high-voltage operation.
446️⃣
Q: PIN diodes are mainly used in
Options:
A) Rectifiers
B) RF switches and attenuators
C) Regulators
D) Light sources
Answer: B) RF switches and attenuators
Explanation:
Their variable resistance property makes them ideal for RF control circuits.
447️⃣
Q: Varactor diodes are used in
Options:
A) Oscillators
B) Frequency modulation circuits
C) Voltage-controlled tuning
D) All of these
Answer: D) All of these
Explanation:
Varactors provide voltage-dependent capacitance, used in tunable circuits and modulators.
448️⃣
Q: In a varactor diode, capacitance is
Options:
A) Constant
B) Inversely proportional to reverse voltage
C) Directly proportional to reverse voltage
D) Independent of voltage
Answer: B) Inversely proportional to reverse voltage
Explanation:
As reverse bias increases, depletion width increases and capacitance decreases.
449️⃣
Q: A Schottky diode is also known as
Options:
A) Hot-carrier diode
B) Cold diode
C) Light-emitting diode
D) Rectifier diode
Answer: A) Hot-carrier diode
Explanation:
Due to metal–semiconductor junction, current is carried by hot electrons.
450️⃣
Q: The main advantage of Schottky diode is
Options:
A) High voltage rating
B) Fast switching speed
C) High reverse recovery
D) Light emission
Answer: B) Fast switching speed
Explanation:
Schottky diodes have negligible storage charge, giving them nanosecond switching capability.
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