Explore topic-wise MCQs in Testing Subject.

This section includes 657 Mcqs, each offering curated multiple-choice questions to sharpen your Testing Subject knowledge and support exam preparation. Choose a topic below to get started.

1.

There is a need of transformer for ………………..

A. half-wave rectifier
B. centre-tap full-wave rectifier
C. bridge full-wave rectifier
D. none of the above
Answer» C. bridge full-wave rectifier
Discussion
2.

The ripple factor of a half-wave rectifier is ………………

A. 2
B. 1.21
C. 2.5
D. 0.48
Answer» E.
Discussion
3.

The disadvantage of a half-wave rectifier is that the……………….`

A. components are expensive
B. diodes must have a higher power rating
C. output is difficult to filter
D. none of the above
Answer» D. none of the above
Discussion
4.

Mains a.c. power is converrted into d.c. power for ……………

A. lighting purposes
B. heaters
C. using in electronic equipment
D. none of the above
Answer» D. none of the above
Discussion
5.

………. rectifier has the lowest forward resistance

A. solid state
B. vacuum tube
C. gas tube
D. none of the above
Answer» B. vacuum tube
Discussion
6.

A zener diode has ………….. breakdown voltage

A. undefined
B. sharp
C. Zero
D. none of the above
Answer» C. Zero
Discussion
7.

A zener diode is …………………. device

A. a non-linear
B. a linear
C. an amplifying
D. none of the above
Answer» B. a linear
Discussion
8.

A series resistance is connected in the zener circuit to………..

A. properly reverse bias the zener
B. protect the zener
C. properly forward bias the zener
D. none of the above
Answer» C. properly forward bias the zener
Discussion
9.

In the breakdown region, a zener didoe behaves like a …………… source.

A. constant voltage
B. constant current
C. constant resistance
D. none of the above
Answer» B. constant current
Discussion
10.

A zener diode utilizes ……….. characteristics for its operation.

A. forward
B. reverse
C. both forward and reverse
D. none of the above
Answer» C. both forward and reverse
Discussion
11.

A zener diode is always ………… connected.

A. reverse
B. forward
C. either reverse or forward
D. none of the above
Answer» B. forward
Discussion
12.

The doping level in a zener diode is …………… that of a crystal diode

A. the same as
B. less than
C. more than
D. none of the above
Answer» D. none of the above
Discussion
13.

A zener diode is used as …………….

A. an amplifier
B. a voltage regulator
C. a rectifier
D. a multivibrator
Answer» C. a rectifier
Discussion
14.

A zener diode has ………..

A. one pn junction
B. two pn junctions
C. three pn junctions
D. none of the above
Answer» B. two pn junctions
Discussion
15.

If the doping level in a crystal diode is increased, the width of depletion layer………..

A. remains the same
B. is decreased
C. in increased
D. none of the above
Answer» D. none of the above
Discussion
16.

When a crystal diode is used as a rectifier, the most important consideration is ……….

A. forward characteristic
B. doping level
C. reverse characteristic
D. PIC rating
Answer» E.
Discussion
17.

A crystal diode utilises …………….. characteristic for rectification

A. reverse
B. forward
C. forward or reverse
D. none of the above
Answer» C. forward or reverse
Discussion
18.

A crystal diode is a …………… device

A. non-linear
B. bilateral
C. linear
D. none of the above
Answer» B. bilateral
Discussion
19.

When the crystal current diode current is large, the bias is …………

A. forward
B. inverse
C. poor
D. reverse
Answer» B. inverse
Discussion
20.

When the graph between current through and voltage across a device is a straight line, the device is referred to as ……………….

A. linear
B. active
C. nonlinear
D. passive
Answer» B. active
Discussion
21.

The knee voltage of a crystal diode is approximately equal to ………….

A. applied voltage
B. breakdown voltage
C. forward voltage
D. barrier potential
Answer» E.
Discussion
22.

If the doping level of a crystal diode is increased, the breakdown voltage………….

A. remains the same
B. is increased
C. is decreased
D. none of the above
Answer» D. none of the above
Discussion
23.

The PIV rating of a crystal diode is ………….. that of equivalent vacuum diode

A. the same as
B. lower than
C. more than
D. none of the above
Answer» C. more than
Discussion
24.

If the temperature of a crystal diode increases, then leakage current ……..

A. remains the same
B. decreases
C. increases
D. becomes zero
Answer» D. becomes zero
Discussion
25.

The leakage current in a crystal diode is due to …………….

A. minority carriers
B. majority carriers
C. junction capacitance
D. none of the above
Answer» B. majority carriers
Discussion
26.

The ratio of reverse resistance and forward resistance of a germanium crystal diode is about ………….

A. 1 : 1
B. 100 : 1
C. 1000 : 1
D. 40,000 : 1
Answer» E.
Discussion
27.

An ideal crystal diode is one which behaves as a perfect ………..when forward biased.

A. conductor
B. insulator
C. resistance material
D. none of the above
Answer» B. insulator
Discussion
28.

The d.c. resistance of a crystal diode is ………….. its a.c. resistance

A. the same as
B. more than
C. less than
D. none of the above
Answer» D. none of the above
Discussion
29.

A crystal diode is used as ……………

A. an amplifier
B. a rectifier
C. an oscillator
D. a voltage regulator
Answer» C. an oscillator
Discussion
30.

The forward voltage drop across a silicon diode is about …………………

A. 2.5 V
B. 3 V
C. 10 V
D. 0.7 V
Answer» E.
Discussion
31.

The reverse current in a diode is of the order of ……………….

A. kA
B. mA
C. μA
D. A
Answer» D. A
Discussion
32.

If the arrow of crystal diode symbol is positive w.r.t. bar, then diode is ………….. biased.

A. forward
B. reverse
C. either forward or reverse
D. none of the above
Answer» B. reverse
Discussion
33.

A crystal diode has forward resistance of the order of ……………

A. kΩ
B. Ω
C. MΩ
D. none of the above
Answer» C. MΩ
Discussion
34.

A crystal diode has ………

A. one pn junction
B. two pn junctions
C. three pn junctions
D. none of the above
Answer» B. two pn junctions
Discussion