Transistor Audio Power Amplifiers(Electrical Engineering ) Questions and answers for exam Preparation

Question 1. The output stage of a multistage amplifier usually employs ___________

Push-pull amplifier
Preamplifier
Class A power amplifier
None of the above

Explanation:-

Answer: Option A. -> Push-pull amplifier

Question 2. 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?

20 W
40 W
10 W
80 W

Explanation:-

Answer: Option A. -> 20 W

Question 3. ___________ coupling is generally employed in power amplifiers

Transformer
RC
direct
Impedance

Explanation:-

Answer: Option A. -> Transformer

Question 4. The maximum efficiency of resistance loaded class A power amplifier is

5%
50%
30%
25%

Explanation:-

Answer: Option D. -> 25%

Question 5. The disadvantage of impedance matching is that it ___________

Gives distorted output
Gives low power output
Requires a transformer
None of the above

Explanation:-

Answer: Option A. -> Gives distorted output

Question 6. If a transistor is operated in such a way that output current flows for 60° of the input signal, then it is ___________ operation

Class A
Class B
Class C
None of the above

Explanation:-

Answer: Option C. -> Class C

Question 7. If the zero signal dissipation of a transistor is 1W, then power rating of the transistor should be at least ___________

5 W
33 W
75 W
1 W

Explanation:-

Answer: Option D. -> 1 W

Question 8. When no signal is applied, the approximate collector efficiency of class A power amplifier is

10%
0%
25%
50%

Explanation:-

Answer: Option B. -> 0%

Question 9. The push-pull circuit must use ___________ operation

Class A
Class C
Class B
Class AB

Explanation:-

Answer: Option C. -> Class B

Question 10. The most costly coupling is ___________ coupling

RC
Direct
Impedance
Transformer

Explanation:-

Answer: Option D. -> Transformer