MULTI STAGE TRANSISTOR AMPLIFIERS Objective Questions and Answers

MULTI STAGE TRANSISTOR AMPLIFIERS Objective Questions and Answers :-


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


  1. One stage
  2. Two stages
  3. Three stages
  4. More than one stages

Ans : 4

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


  1. Voltage
  2. Current
  3. Power
  4. None of the above

Ans : 1

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


  1. Changes abruptly with frequency
  2. Is constant
  3. Changes uniformly with frequency
  4. None of the above

Ans : 2

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


  1. Amplifier level output is kept constant
  2. Amplifier frequency is held constant
  3. Generator frequency is held constant
  4. Generator output level is held constant

Ans : 4

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


  1. Good impedance matching
  2. Economy
  3. High efficiency
  4. None of the above

Ans : 2

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


  1. RC
  2. Transformer
  3. Direct
  4. None of the above

Ans : 3

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


  1. Power
  2. Voltage
  3. Current
  4. None of the above

Ans : 1

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


  1. To pass d.c. between the stages
  2. Not to attenuate the low frequencies
  3. To dissipate high power
  4. None of the above

Ans : 2

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


  1. 100 pF
  2. 0.1 µF
  3. 0.01 µF
  4. 10 µF

Ans : 4

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


  1. 0
  2. 1
  3. 1
  4. 10

Ans : 1

11. When a multistage amplifier is to amplify d.c. signal, then one must use …….. coupling


  1. RC
  2. Transformer
  3. Direct
  4. None of the above

Ans : 3

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


  1. RC
  2. Transformer
  3. Direct
  4. Impedance

Ans : 2

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


  1. In db
  2. In volts
  3. As a number
  4. None of the above

Ans : 1

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


  1. Collector voltage is stepped up
  2. c. resistance is low
  3. collector voltage is stepped down
  4. none of the above

Ans : 2

15. Transformer coupling is generally employed when load resistance is ………


  1. Large
  2. Very large
  3. Small
  4. 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 ……….


  1. 600 db
  2. 24 db
  3. 14 db
  4. 27 db

Ans : 4

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


  1. RC coupling
  2. Transformer coupling
  3. Direct coupling
  4. Impedance coupling

Ans : 2

18. The ear is not sensitive to ………….


  1. Frequency distortion
  2. Amplitude distortion
  3. Frequency as well as amplitude distortion
  4. None of the above

Ans : 1

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


  1. There is considerable power loss
  2. There is hum in the output
  3. Electrical size of coupling capacitor becomes very large
  4. None of the above

Ans : 3

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


  1. Step up
  2. Step down
  3. Same turn ratio
  4. None of the above

Ans : 2


21. The lower and upper cut off frequencies are also called ………………… frequencies

  1. Sideband
  2. Resonant
  3. Half-resonant
  4. Half-power

Ans : 4

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


  1. 30 db
  2. 60 db
  3. 120 db
  4. 600 db

Ans : 2

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


  1. 60 db
  2. 30 db
  3. 120 db
  4. 600 db

Ans : 1

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


  1. 50%
  2. 35%
  3. 26%
  4. 22%

Ans : 3

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


  1. 40%
  2. 80%
  3. 20%
  4. 25%

Ans : 1

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


  1. Good
  2. Very good
  3. Excellent
  4. Poor

Ans : 4

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


  1. RC coupling
  2. Transformer coupling
  3. Direct coupling
  4. 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 …………


  1. Power loss in the coupling device
  2. Loading effect of the next stage
  3. The use of many transistors
  4. The use of many capacitors

Ans : 2

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


  1. It is a simple unit
  2. Calculations become easy
  3. Human ear response is logarithmic
  4. None of the above

Ans : 3

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


  1. 5 db
  2. 2 db
  3. 10 db
  4. 3 db

Ans : 4

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


  1. 3 db
  2. 66 db
  3. 20 db
  4. 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?


  1. 8 db
  2. 6 db
  3. 5 db
  4. 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 ?


  1. 2 W
  2. 6 W
  3. 68 W
  4. 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?


  1. 5 mV
  2. 2 mV
  3. 8 mV
  4. 5 mV

Ans : 4

35. RC coupling is generally confined to low power applications because of ………


  1. Large value of coupling capacitor
  2. Low efficiency
  3. Large number of components
  4. None of the above

Ans : 2

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


  1. Changes in temperature cause thermal instability
  2. Circuit becomes heavy and costly
  3. It becomes difficult to bias the circuit
  4. None of the above

Ans : 1

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


  1. Block a.c.
  2. Separate bias of one stage from another
  3. Increase thermal stability
  4. None of the above

Ans : 2

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


  1. Resonant
  2. Sideband
  3. 3 db
  4. None of the above

Ans : 3

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


  1. More than
  2. The same as
  3. Less than
  4. Data insufficient

Ans : 1

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


  1. 1 µF
  2. 100 pF
  3. 0.01 µF
  4. 50 µF

Ans : 4