1 $At absolute zero temperature (), an intrinsic semiconductor behaves as a/an:$

A.

Perfect conductor

B.

Insulator

C.

Superconductor

D.

Variable resistor

2 $When a pure semiconductor is doped with a pentavalent impurity, it becomes a/an:$

A.

p-type semiconductor

B.

n-type semiconductor

C.

Intrinsic semiconductor

D.

Insulator

3 $In a p-type semiconductor, the majority charge carriers are:$

A.

Electrons

B.

Holes

C.

Positive ions

D.

Negative ions

4 $Which of the following equations correctly represents the Mass-Action Law for semiconductors under thermal equilibrium?$

A.

B.

C.

D.

5 $In an n-type semiconductor, the Fermi energy level lies:$

A.

Exactly in the middle of the bandgap

B.

Closer to the valence band

C.

Closer to the conduction band

D.

Inside the valence band

6 $An ideal diode in the forward-biased condition acts as a/an:$

A.

Open circuit

B.

Short circuit

C.

Current source

D.

Voltage source

7 $The depletion region of an unbiased p-n junction diode contains:$

A.

Free electrons and holes

B.

Only free electrons

C.

Only free holes

D.

Immobile positive and negative ions

8 $What is the net current flowing through an unbiased p-n junction diode?$

A.

Maximum

B.

Zero

C.

Equal to the reverse saturation current

D.

Equal to the forward current

9 $When a p-n junction diode is forward-biased, the width of the depletion region:$

A.

Increases

B.

Decreases

C.

Remains unchanged

D.

Alternates periodically

10 $When a p-n junction diode is reverse-biased, it offers:$

A.

Low resistance

B.

Zero resistance

C.

High resistance

D.

Negative resistance

11 $The typical knee voltage (barrier potential) for a Silicon diode at room temperature is approximately:$

A.

B.

C.

D.

12 $Which of the following represents the correct Shockley diode equation?$

A.

B.

C.

D.

13 $At room temperature (), the thermal voltage () is approximately:$

A.

B.

C.

D.

14 $What is the formula for the dynamic resistance () of a forward-biased diode?$

A.

B.

C.

D.

15 $How does the reverse saturation current () of a diode behave with an increase in temperature?$

A.

It halves for every rise

B.

It doubles for every rise

C.

It remains constant

D.

It decreases linearly

16 $For a constant forward current, the barrier potential of a Silicon diode changes with temperature at a rate of approximately:$

A.

B.

C.

D.

17 $In the V-I characteristics of a p-n junction diode, the forward current rises exponentially after surpassing the:$

A.

Breakdown voltage

B.

Peak inverse voltage

C.

Knee voltage

D.

Pinch-off voltage

18 $Zener breakdown occurs predominantly in diodes that are:$

A.

Lightly doped

B.

Moderately doped

C.

Heavily doped

D.

Intrinsic

19 $Avalanche breakdown in a reverse-biased diode is caused by:$

A.

Direct rupture of covalent bonds by an electric field

B.

Impact ionization due to high-velocity minority carriers

C.

Thermal runaway melting the junction

D.

Spontaneous electron-hole recombination

20 $The breakdown voltage of a typical Zener diode has a negative temperature coefficient, whereas Avalanche breakdown has a:$

A.

Negative temperature coefficient

B.

Positive temperature coefficient

C.

Zero temperature coefficient

D.

Exponential temperature coefficient

21 $To use a Zener diode as a voltage regulator, it must be operated in the:$

A.

Forward bias region

B.

Unbiased condition

C.

Reverse breakdown region

D.

Reverse saturation region

22 $In a Zener voltage regulator circuit, the Zener diode is connected in:$

A.

Series with the load and forward-biased

B.

Series with the load and reverse-biased

C.

Parallel with the load and forward-biased

D.

Parallel with the load and reverse-biased

23 $Line regulation in a power supply refers to the ability to maintain a constant output voltage despite changes in:$

A.

Load current

B.

Ambient temperature

C.

Input line voltage

D.

Output load resistance

24 $Load regulation describes the change in output voltage when there is a change in:$

A.

Input voltage

B.

Load current (or load resistance)

C.

Ripple frequency

D.

Transformer turns ratio

25 $The maximum theoretical rectification efficiency of a Half-Wave Rectifier is:$

A.

B.

C.

D.

26 $The maximum theoretical rectification efficiency of a Full-Wave Rectifier is:$

A.

B.

C.

D.

27 $What is the Ripple Factor () of a standard Half-Wave Rectifier?$

A.

$1.21$

B.

$0.48$

C.

$1.11$

D.

$0.50$

28 $What is the Ripple Factor () of a Full-Wave Rectifier?$

A.

$1.21$

B.

$0.48$

C.

$1.11$

D.

$0.50$

29 $What is the Peak Inverse Voltage (PIV) rating required for a diode in a center-tapped Full-Wave Rectifier (where is the peak voltage of half the secondary winding)?$

A.

B.

C.

D.

30 $What is the Peak Inverse Voltage (PIV) of each diode in a Bridge Full-Wave Rectifier (where is the peak secondary voltage)?$

A.

B.

C.

D.

31 $How many diodes are required to construct a Bridge Full-Wave Rectifier?$

A.

1

B.

2

C.

3

D.

4

32 $If the input AC supply frequency is, what is the fundamental frequency of the output ripple in a Full-Wave Rectifier?$

A.

B.

C.

D.

33 $A circuit designed to remove a specific portion of an input waveform without distorting the remaining part is called a:$

A.

Clamper

B.

Clipper

C.

Rectifier

D.

Filter

34 $A Series Positive Clipper circuit operates by:$

A.

Removing the negative half-cycle of the input signal

B.

Removing the positive half-cycle of the input signal

C.

Shifting the entire waveform upwards

D.

Shifting the entire waveform downwards

35 $What is the primary function of a biased clipper?$

A.

To amplify the input signal

B.

To clip the waveform at a specific non-zero DC reference voltage

C.

To convert an AC signal directly to pure DC

D.

To shift the waveform to a new DC level

36 $A circuit that shifts an entire AC waveform to a different DC level without changing its shape is known as a:$

A.

Clipper

B.

Clamper

C.

Voltage Regulator

D.

Inverter

37 $Which of the following components is essential in a Clamper circuit but generally not required in a simple Clipper circuit?$

A.

Diode

B.

Resistor

C.

Capacitor

D.

Inductor

38 $A Light Emitting Diode (LED) emits light when it is:$

A.

Reverse biased

B.

Forward biased

C.

Unbiased

D.

In avalanche breakdown

39 $The physical phenomenon responsible for light emission in an LED is called:$

A.

Thermionic emission

B.

Electroluminescence

C.

Photoluminescence

D.

Photoelectric effect

40 $Which of the following semiconductor materials is commonly used to manufacture visible Light Emitting Diodes?$

A.

Silicon (Si)

B.

Germanium (Ge)

C.

Gallium Arsenide Phosphide (GaAsP)

D.

Carbon (C)

41 $Why are standard Silicon and Germanium diodes not used to make LEDs?$

A.

They are too expensive

B.

They have a direct bandgap

C.

They have an indirect bandgap

D.

Their breakdown voltage is too low

42 $The wavelength () of the light emitted by an LED is related to the bandgap energy () of the semiconductor by which equation?$

A.

B.

C.

D.

43 $Which of the following represents the correct sequential block diagram of a regulated linear DC power supply?$

A.

Transformer Filter Rectifier Regulator

B.

Transformer Rectifier Filter Regulator

C.

Rectifier Transformer Regulator Filter

D.

Regulator Rectifier Filter Transformer

44 $The primary purpose of the filter circuit in a DC power supply is to:$

A.

Step down the AC input voltage

B.

Convert AC to pulsating DC

C.

Remove AC ripples from the pulsating DC output

D.

Regulate the output voltage against load variations

45 $In a simple capacitor filter power supply, the capacitor is connected:$

A.

In series with the load

B.

In parallel with the load

C.

In series with the transformer primary

D.

In parallel with the AC mains

46 $The purpose of a voltage regulator in a power supply design is to:$

A.

Increase the ripple factor

B.

Maintain a constant output voltage despite line and load variations

C.

Convert DC voltage back to AC voltage

D.

Step up the output DC voltage

47 $In a diode datasheet, what does the parameter denote?$

A.

Peak inverse current

B.

Maximum average forward current

C.

Surge current

D.

Reverse leakage current

48 $In a diode datasheet, the Reverse Recovery Time () is a critical parameter that determines the diode's:$

A.

Maximum power dissipation

B.

Maximum operating frequency (switching speed)

C.

Forward voltage drop

D.

Thermal resistance

49 $According to a standard diode datasheet, the parameter represents the:$

A.

Maximum repetitive peak reverse voltage

B.

RMS working reverse voltage

C.

Minimum forward breakdown voltage

D.

Maximum reverse recovery voltage

50 $What is indicated by the parameter in a semiconductor diode datasheet?$

A.

Maximum Peak Diode Current

B.

Maximum Power Dissipation

C.

Phase Delay maximum

D.

Potential Difference maximum

Unit 1 - Practice Quiz