Power Amplifiers Questions and Answers
The Power Amplifiers questions with answers section covers important electronics concepts such as Class A, B, AB, and C amplifiers, efficiency, distortion, and transistor operation. These electronics aptitude questions and answers are frequently asked in GATE, BEL, DRDO, and campus placement exams. Understanding how power amplifiers boost signal strength is essential for ECE and EE students. Each question is explained with diagrams and theory, helping you prepare thoroughly for both academic and technical interviews in electronics-based roles.
Power Amplifiers
Showing 10 of
55 questions
31. Which of the following describe(s) a power amplifier?
- It can handle large power.
- It can handle large current.
- It does not provide much voltage gain.
- All of the above
32. Categorize the power efficiency of each class of amplifier, from worst to best.
- A, B, AB, D
- A, AB, D, B
- A, AB, B, D
33. In a class AB amplifier, if the VBE drops are not matched to the diode drops or if the diodes are not in thermal equilibrium with the transistors, this can result in
- a current mirror.
- diode separation.
- crossover distortion.
- thermal runaway.
34. The least efficient amplifier among all classes is
- class B.
- class A.
- class AB.
- class C.
35. In practice, the efficiency of a capacitively coupled class A amplifier is about ________%.
- 25
- 40
- 70
- 10
36. A class A amplifier has a voltage gain of 30 and a current gain of 25. What is the power gain?
- 30
- 25
- 1.2
- 750
37. Which of the following transistors has been quite popular as the driver device for class D amplification?
- BJT
- FET
- UJT
- MOSFET
38. Which of the following is (are) the disadvantage(s) of a class B complementary-symmetry circuit?
- It needs two separate voltage sources.
- There is crossover distortion in the output signal.
- It does not provide exact switching of one transistor off and the other on at the zero-voltage condition.
- All of the above
39. Which of the power amplifiers has the lowest overall efficiency?
- Class A
- Class B or AB
- Class C
- Class D
40. Calculate the efficiency of a class B amplifier for a supply voltage of VCC = 20 V with peak output voltage of VL(p) = 18 V. Assume RL = 16.
- 78.54%
- 75%
- 70.69%
- 50%