1.4 Diode MCQs v2

License Preparation NepalNEC ELECTRONICS

Full marks: 25 · Questions: 25

01Semiconductor Diodes

The arrow direction in the schematic diode symbol indicates:

Direction of electron flow

Direction of hole flow (Direction of conventional current)

Opposite to the direction of hole flow

None of the above

02Semiconductor Diodes

The knee voltage (cut-in barrier voltage) of a standard silicon PN junction diode is approximately:

0.2 V

0.7 V

0.8 V

1.0 V

03Semiconductor Diodes

When an ideal diode is forward biased, its operational behavior is equivalent to:

An off-switch

An On-switch

A high resistance

None of the above

04Semiconductor Diodes

Under normal reverse bias voltage applied to a silicon diode, the reverse leakage current is in the:

100 mA range

order of μA to nA

1000 μA range

None of these

05Semiconductor Diodes

Avalanche breakdown in a reverse-biased PN junction diode occurs when:

Potential barrier is reduced to zero

Forward current exceeds certain value

Reverse bias voltage exceeds a certain critical threshold

None of these

06Semiconductor Diodes

The reverse saturation current in a silicon PN junction diode approximately doubles for every:

20°C rise in temp.

50°C rise in temp.

60°C rise in temp.

10°C rise in temp.

07Semiconductor Diodes

A forward DC potential of 10 V is applied across a silicon diode (cut-in 0.7 V) in series with a 1 kΩ resistor. The resulting forward current is:

10 mA

9.3 mA

0.7 mA

0 mA

08Semiconductor Diodes

When reverse bias is applied across a semiconductor diode, it acts to:

Raise the internal potential barrier height

Lower the internal potential barrier height

Increase majority-carrier current exponentially

None of these

09Zener and Special Diodes

The primary operational characteristic of a Zener diode is that:

it operates in the reverse breakdown region as a constant voltage reference

it is a constant current device

it conducts only when forward biased

none of the above

10Zener and Special Diodes

Light Emitting Diodes (LEDs) are typically fabricated from which compound semiconductor material?

GeSi

C and Si

Gallium Arsenide (GaAs)

none of the above

11Semiconductor Diodes

Testing a properly functioning PN junction diode with an ohmmeter should indicate:

high resistance when forward or reverse biased

low resistance when forward or reverse biased

high resistance when reverse biased and low resistance when forward biased

high resistance when forward biased and low resistance when reverse biased

12Semiconductor Diodes

A PN junction diode conducts significant current when:

both the n-type and p-type regions have the same electrical potential

the n-type material is more positive than the p-type material

the p-type material is more positive than the n-type material

there is no external potential applied

13Zener and Special Diodes

The semiconductor optoelectronic device predominantly used in seven-segment numeric displays is the:

Zener diode

Photodiode

Light Emitting Diode (LED)

LASER diode

14Semiconductor Physics

A band diagram displaying a Valence Band (VB), Conduction Band (CB), and Forbidden Energy Gap (Eg) is termed:

the single energy level of an electron

the discrete atomic orbit diagram

the energy transfer diagram

the energy band diagram

15Semiconductor Diodes

The forward-biased resistance of a semiconductor diode is:

much larger than its reverse-biased resistance

double its reverse-biased resistance

much smaller than its reverse-biased resistance

none of these

16Zener and Special Diodes

In electronic circuits, a Zener diode is primarily operated in its:

reverse breakdown region

forward active conduction region

zero-bias unbiased region

none of these

17Zener and Special Diodes

If both P and N sides of a junction diode are very heavily doped, its reverse breakdown voltage will:

increase

decrease

remain the same

none of these

18Semiconductor Diodes

The contact potential (barrier potential) of an unbiased silicon PN junction at room temperature is:

0.2 V

0.7 V

0.8 V

1.0 V

19Zener and Special Diodes

A Zener diode is most commonly employed as a:

half wave filter

half wave rectifier

voltage regulator

tuned amplifier

20Zener and Special Diodes

The acronym LED stands for:

light energized diode

light emitting diode

low energy device

low energy dynamo

21Semiconductor Physics

By introducing which type of dopant impurity into an intrinsic semiconductor is a P-type semiconductor created?

trivalent impurity

pentavalent impurity

tetravalent impurity

divalent impurity

22Semiconductor Physics

The net macroscopic electrical charge on an isolated P-type semiconductor crystal is:

positive

electrically neutral

negative

either positive or negative

23Transistor Fundamentals

The primary functional role of a transistor in analog electronics is to perform:

rectification

signal amplification

light emission

heat emission

24Transistor Fundamentals

Transistors are formally categorized as which type of circuit device?

active electronic devices

passive electronic devices

both active and passive devices

neither active nor passive devices

25Transistor Fundamentals

For a Common Emitter (CE) transistor configuration, the output characteristic curves represent a graph of:

IB versus VBE

IB versus VCE

IE versus VCE

IC versus VCE