MULTISTAGE TRANSISTOR AMPLIFIERS Questions :-
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 …………..
0
1
1
10
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
c. 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