Explore topic-wise MCQs in Electrical Engineering.

This section includes 79 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering knowledge and support exam preparation. Choose a topic below to get started.

51.

*/*_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
52.

*/*_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
53.

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

A. 5%
B. 50%
C. 30%
D. 25%
Answer» E.
Discussion
54.

_ 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
55.

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

A. Dual
B. Push-pull
C. Symmetrical
D. Differential
Answer» C. Symmetrical
Discussion
56.

_ 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
57.

_ 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
58.

_ 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
59.

_ 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
60.

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
61.

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
62.

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
63.

The most costly coupling is ___________ coupling$?

A. RC
B. Direct
C. Impedance
D. Transformer
Answer» E.
Discussion
64.

Class ___________ operation gives the maximum distortion$?

A. A
B. B
C. C
D. AB
Answer» D. AB
Discussion
65.

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
66.

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
67.

___________ coupling is generally employed in power amplifiers

A. Transformer
B. RC
C. direct
D. Impedance
Answer» B. RC
Discussion
68.

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
69.

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
70.

The push-pull circuit must use ___________ operation

A. Class A
B. Class C
C. Class B
D. Class AB
Answer» D. Class AB
Discussion
71.

Class C power amplifier has the highest collector efficiency

A. C
B. A
C. B
D. AB
Answer» B. A
Discussion
72.

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

A. 30%
B. 50%
C. 80%
D. 45%
Answer» C. 80%
Discussion
73.

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
74.

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
75.

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
76.

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
77.

The maximum collector efficiency of class B operation is ___________

A. 50%
B. 90%
C. 5%
D. 5%
Answer» E.
Discussion
78.

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
79.

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