# Classification of Output Stages MCQ’s

This set of Electronic Devices & Circuits Multiple Choice Questions & Answers (MCQs) focuses on “Classification of Output Stages”.

1. Which of the power amplifiers has the lowest overall efficiency?
a) Class C
b) Class A
c) Class B or AB
d) Class D

2. 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 .
a) 78.54%
b) 75%
c) 70.69%
d) 50%

3. A class A amplifier with RC = 3.3 k and RE = 1.2 k has a VCC = 20 V. Find IC(sat).
a) 4.4mA
b) 6.1mA
c) 20mA
d) 16.7mA

4. For BJT power transistors, the collector terminal is always connected to the transistor’s case________
a) for easy circuit connection
b) to prevent shorts
c) because the collector terminal is the critical terminal for heat dissipation
d) because the collector terminal is located nearest the case

5. Which of the push-pull amplifiers is presently the most popular form of the class B power amplifier?
a) Quasi-complementary
b) Transformer-coupled
c) Complementary-symmetry
d) Symmetry

6. Which of the power amplifiers is not suitable as audio amplifiers?
a) Class A
b) Class B
c) Class C
d) Class D

7. Which operation class is generally used in radio or communications?
a) A
b) B
c) C
d) D

8. Calculate the harmonic distortion component for an output signal having a fundamental amplitude of 3 V and a second harmonic amplitude of 0.25 V.
a) 3.83%
b) 38.3%
c) 83.3%
d) 8.33%

9. Which type of amplifier uses pulse (digital) signals in its operation?
a) Class A
b) Class B or AB
c) Class C
d) Class D

10. What is the maximum efficiency of a class B circuit?
a) 90%
b) 78.5%
c) 40%
d) 50%