Operational Amplifier and Its Applications MCQs

Question 1

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

Accepted Answer

10 V

Answer

1 V

Answer

100 V

Answer

20 V

Question 2

The output signal voltage and current of a power amplifier are 5 V and 200 mA;the values being r.m.s. What is the power output?

Accepted Answer

1 W

Answer

2 W

Answer

4 W

Answer

none of the above

Question 3

The push-pull circuit operation.

Accepted Answer

class B

Answer

class A

Answer

class C

Answer

class AB

Question 4

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

Accepted Answer

20 W

Answer

40 W

Answer

10 W

Answer

80 W

Question 5

What turn ratio (N /N) of transformer is required to mate% 4 LI speaker to a transistor having an output impedance of 80001?

Accepted Answer

44.7

Answer

35.2

Answer

54.3

Answer

none of the above

Question 6

A transformer coupled class A power amplifier has a load of 100 L2 on the secondary. If the turn ratio is 10: 1, what is the value of load appearing on the primary?

Accepted Answer

10 ki2

Answer

5kI

Answer

20 ka

Answer

1001d2

Question 7

Power amplifiers generally use transformer coupling because transformer permits

Accepted Answer

impedance matching

Answer

cooling of the circuit

Answer

distortionless output

Answer

good frequency response

Question 8

The output transformer used in a power amplifier is a _____ transformer.

Accepted Answer

step-down

Answer

1: I ratio

Answer

step-up

Answer

none of the above

Question 9

The most important consideration in power amplifiers is ____ biasing the circuit

Accepted Answer

to keep the transformer cool

Answer

collector efficiency

Answer

none of the above