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.

*/*_The pulsating d.c. applied to power amplifier causes ___________?

A. Burning of transistor
B. Hum in the circuit
C. Excessive forward voltage
D. None of the above
Answer» C. Excessive forward voltage
Discussion
2.

*/*_Low efficiency of a power amplifier results in ___________?

A. Low forward bias
B. Less battery consumption
C. More battery consumption
D. None of the above
Answer» D. None of the above
Discussion
3.

_ The maximum efficiency of resistance loaded class A power amplifier is$?

A. 5%
B. 50%
C. 30%
D. 25%
Answer» E.
Discussion
4.

_ Low efficiency of a power amplifier results in ___________$?

A. Low forward bias
B. Less battery consumption
C. More battery consumption
D. None of the above
Answer» D. None of the above
Discussion
5.

_ A 2-transistor class B power amplifier is commonly called ___________ amplifier$?

A. Dual
B. Push-pull
C. Symmetrical
D. Differential
Answer» C. Symmetrical
Discussion
6.

_ When no signal is applied, the approximate collector efficiency of class A power amplifier is$?

A. 10%
B. 0%
C. 25%
D. 50%
Answer» C. 25%
Discussion
7.

_ An AF amplifier is shielded to ___________$?

A. Keep the amplifier cool
B. Protect from rusting
C. Prevent induction due to stray magnetic fields
D. None of the above
Answer» D. None of the above
Discussion
8.

_ What turn ratio (Np/Ns) of transformer is required to match 4 Ω speaker to a transistor having an output impedance of 8000 O?$?

A. 2
B. 7
C. 3
D. None of the above
Answer» C. 3
Discussion
9.

_ The pulsating d.c. applied to power amplifier causes ___________$?

A. Burning of transistor
B. Hum in the circuit
C. Excessive forward voltage
D. None of the above
Answer» C. Excessive forward voltage
Discussion
10.

The class B push-pull circuit can deliver 100 W of a.c. output power. What should be the minimum power rating of each transistor?$?

A. 20 W
B. 40 W
C. 10 W
D. 80 W
Answer» B. 40 W
Discussion
11.

When a transistor is cut off___________$?

A. Maximum voltage appears across transistor
B. Maximum current flows
C. Maximum voltage appears across load
D. None of the above
Answer» B. Maximum current flows
Discussion
12.

Transformer coupling can be used in ___________ amplifiers$?

A. Either power or voltage
B. Only power
C. Only voltage
D. None of the above
Answer» B. Only power
Discussion
13.

The most costly coupling is ___________ coupling$?

A. RC
B. Direct
C. Impedance
D. Transformer
Answer» E.
Discussion
14.

Class ___________ operation gives the maximum distortion$?

A. A
B. B
C. C
D. AB
Answer» D. AB
Discussion
15.

The most important consideration in power amplifier is ___________$?

A. Biasing the circuit
B. Collector efficiency
C. To keep the transformer cool
D. None of the above
Answer» C. To keep the transformer cool
Discussion
16.

Power amplifiers handle ___________ signals compare to voltage amplifiers$?

A. Small
B. Very small
C. Large
D. None of the above
Answer» D. None of the above
Discussion
17.

___________ coupling is generally employed in power amplifiers

A. Transformer
B. RC
C. direct
D. Impedance
Answer» B. RC
Discussion
18.

A transformer coupled class A power amplifier has a load of 100 Ω on the secondary. If the turn ratio is 10:1, what is the value of load appearing on the primary?$

A. 5 kΩ
B. 20 kΩ
C. 100 kΩ
D. 10 kΩ
Answer» E.
Discussion
19.

The output transformer used in a power amplifier is a ___________ transformer

A. 1:1 ratio
B. Step-up
C. Step-down
D. None of the above
Answer» D. None of the above
Discussion
20.

The push-pull circuit must use ___________ operation

A. Class A
B. Class C
C. Class B
D. Class AB
Answer» D. Class AB
Discussion
21.

Class C power amplifier has the highest collector efficiency

A. C
B. A
C. B
D. AB
Answer» B. A
Discussion
22.

The maximum efficiency of transformer coupled class A power amplifier is ___________

A. 30%
B. 50%
C. 80%
D. 45%
Answer» C. 80%
Discussion
23.

The output stage of a multistage amplifier usually employs ___________

A. Push-pull amplifier
B. Preamplifier
C. Class A power amplifier
D. None of the above
Answer» B. Preamplifier
Discussion
24.

What will be the collector efficiency of a power amplifier having zero signal power dissipation of 5 watts and a.c. power output of 2 watts?

A. 20%
B. 80%
C. 40%
D. 50%
Answer» D. 50%
Discussion
25.

In class A operation, the operating point is generally located ___________ of the d.c. load line.

A. At cut off point
B. At the middle
C. At saturation point
D. None of the above
Answer» C. At saturation point
Discussion
26.

If a transistor is operated in such a way that output current flows for 60° of the input signal, then it is ___________ operation#

A. Class A
B. Class B
C. Class C
D. None of the above
Answer» D. None of the above
Discussion
27.

The maximum collector efficiency of class B operation is ___________

A. 50%
B. 90%
C. 5%
D. 5%
Answer» E.
Discussion
28.

A class A power amplifier uses ___________

A. Two transistors
B. Three transistors
C. One transistor
D. None of the above
Answer» D. None of the above
Discussion
29.

If the power rating of a transistor is 1W and collector current is 100mA, then maximum allowable collector voltage is ___________

A. 1V
B. 100V
C. 20V
D. 10V
Answer» E.
Discussion