Multistage Transistor Amplifiers Questions And Answers

1. A radio receiver has …………… of amplification

One stage

Two stages

Three stages

More than one stages

Ans : 4

2. RC coupling is used for ………………. amplification

Voltage

Current

Power

None of the above

Ans : 1

3. In an RC coupled amplifier, the voltage gain over mid-frequency

range …………….

Changes abruptly with frequency

Is constant

Changes uniformly with frequency

None of the above

Ans : 2

4. In obtaining the frequency response curve of an amplifier,

the …………

Amplifier level output is kept constant

Amplifier frequency is held constant

Generator frequency is held constant

Generator output level is held constant

Ans : 4

5. An advantage of RC coupling scheme is the ………….

Good impedance matching

Economy

High efficiency

None of the above

Ans : 2

6. The best frequency response is of ………. coupling

RC

Transformer

Direct

None of the above

Ans : 3

7. Transformer coupling is used for ………….. amplification

Power

Voltage

Current

None of the above

Ans : 1

8. In an RC coupling scheme, the coupling capacitor CC must be large

enough ………..

To pass d.c. between the stages

Not to attenuate the low frequencies

To dissipate high power

None of the above

Ans : 2

9. In RC coupling, the value of coupling capacitor is about ……….

100 pF

0.1 μF

0.01 μF

10 μF

Ans : 4

10. The noise factor of an ideal amplifier expressed in db is …………..

0111

0

Ans : 1

11. When a multistage amplifier is to amplify d.c. signal, then one

must use …….. coupling

RC

Transformer

Direct

None of the above

Ans : 3

12. ………….. coupling provides the maximum voltage gain

RC

Transformer

Direct

Impedance

Ans : 2

13. In practice, voltage gain is expressed ……………

In db

In volts

As a number

None of the above

Ans : 1

14. Transformer coupling provides high efficiency because …………

Collector voltage is stepped up

1. resistance is low

collector voltage is stepped down

none of the above

Ans : 2

15. Transformer coupling is generally employed when load resistance

is ………

Large

Very large

Small

None of the above

Ans : 3

16. If a three-stage amplifier has individual stage gains of 10 db, 5 db

and 12 db, then total gain in db is ……….

600 db

24 db

14 db

27 db

Ans : 4

17. The final stage of a multistage amplifier uses ………………

RC coupling

Transformer coupling

Direct coupling

Impedance coupling

Ans : 2

18. The ear is not sensitive to ………….

Frequency distortion

Amplitude distortion

Frequency as well as amplitude distortion

None of the above

Ans : 1

19. RC coupling is not used to amplify extremely low frequencies

because ………

There is considerable power loss

There is hum in the output

Electrical size of coupling capacitor becomes very large

None of the above

Ans : 3

20. In transistor amplifiers, we use ……………. transformer for

impedance matching

Step up

Step down

Same turn ratio

None of the above

Ans : 2

21. The lower and upper cut off frequencies are also

called ………………… frequencies

Sideband

Resonant

Half-resonant

Half-power

Ans : 4

22. A gain of 1,000,000 times in power is expressed by …………….

30 db

60 db

120 db

600 db

Ans : 2

23. A gain of 1000 times in voltage is expressed by …………..

60 db

30 db

120 db

600 db

Ans : 1

24. 1 db corresponds to ………….. change in power level

50%

35%

26%

22%

Ans : 3

25. 1 db corresponds to …………. change in voltage or current level

40%

80%

20%

25%

Ans : 1

26. The frequency response of transformer coupling is ………….

Good

Very good

Excellent

Poor

Ans : 4

27. In the initial stages of a multistage amplifier, we use ………..

RC coupling

Transformer coupling

Direct coupling

None of the above

Ans : 1

28. The total gain of a multistage amplifier is less than the product of

the gains of individual stages due to …………

Power loss in the coupling device

Loading effect of the next stage

The use of many transistors

The use of many capacitors

Ans : 2

29. The gain of an amplifier is expressed in db because ………..

It is a simple unit

Calculations become easy

Human ear response is logarithmic

None of the above

Ans : 3

30. If the power level of an amplifier reduces to half, the db gain will

fall by …….

5 db

2 db

10 db

3 db

Ans : 4

31. A current amplification of 2000 is a gain of …………….

3 db

66 db

20 db

200 db

Ans : 2

32. An amplifier receives 0.1 W of input signal and delivers 15 W of

signal power. What is the power gain in db?

8 db

6 db

5 db

4 db

Ans : 1

33. The power output of an audio system is 18 W. For a person to

notice an increase in the output (loudness or sound intensity) of the

system, what must the output power be increased to ?

2 W

6 W

68 W

None of the above

Ans : 3

34. The output of a microphone is rated at -52 db. The reference level

is 1V under specified conditions. What is the output voltage of this

microphone under the same sound conditions?

5 mV

2 mV

8 mV

5 mV

Ans : 4

35. RC coupling is generally confined to low power applications

because of ………

Large value of coupling capacitor

Low efficiency

Large number of components

None of the above

Ans : 2

36. The number of stages that can be directly coupled is limited

because ……..

Changes in temperature cause thermal instability

Circuit becomes heavy and costly

It becomes difficult to bias the circuit

None of the above

Ans : 1

37. The purpose of RC or transformer coupling is to …………

Block a.c.

Separate bias of one stage from another

Increase thermal stability

None of the above

Ans : 2

38. The upper or lower cut off frequency is also called …………..

frequency

Resonant

Sideband

3 db

None of the above

Ans : 3

39. The bandwidth of a single stage amplifier is …………. that of a

multistage amplifier

More than

The same as

Less than

Data insufficient

Ans : 1

40. The value of emitter capacitor CE in a multistage amplifier is

about ……..

1 μF

100 pF

0.01 μF

50 μF

Ans : 4

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