SINGLE STAGE TRANSISTOR AMPLIFIERS Questions :-
1. A single stage transistor amplifier contains ……………. and associated circuitry
Two transistors
One transistor
Three transistor
None of the above
Ans : 2
2. The phase difference between the output and input voltages of a CE amplifier is ………………..
180o
0o
90o
270o
Ans : 1
3. It is generally desired that a transistor should have …………….. input impedance
Low
Very low
High
Very high
Ans : 3
4. When an a.c. signal is applied to an amplifier, ,the operating point moves along …………….
c. load line
c. load line
both d.c. and a.c. load lines
none of the above
Ans : 2
5. If the collector supply is 10V, then collector cut off voltage under d.c. conditions is ………….
20 V
5 V
2 V
10 V
Ans : 4
6. In the zero signal conditions, a transistor sees ……………….. load
c.
c.
both d.c. and a.c.
none of the above
Ans : 1
7. The input capacitor in an amplifier is the ……………….. capacitor
Coupling
Bypass
Leakage
None of the above
Ans : 1
8. The point of intersection of d.c. and a.c. load lines is called ……………..
Saturation point
Cut off point
Operating point
None of the above
Ans : 3
9. The slope of a.c. load line is ……………… that of d.c. load line
The same as
More than
Less than
None of the above
Ans : 2
10. If a transistor amplifier draws 2mA when input voltage is 10 V, then its input impedance is ………..
20 kΩ
2 kΩ
10 kΩ
5 kΩ
Ans : 4
11. When a transistor amplifier is operating, the current in any branch is ……………
Sum of a.c. and d.c.
c. only
c. only
difference of a.c. and d.c.
Ans : 1
12. The purpose of capacitors in a transistor amplifier is to ………………
Protect the transistor
Cool the transistor
Couple or bypass a.c. component
Provide biasing
Ans : 3
13. In the d.c. equivalent circuit of a transistor amplifier, the capacitors are considered ……………..
Short
Open
Partially short
None of the above
Answer : 2
14. In a CE amplifier, voltage gain = ……………. x RAC/Rin
α
(1 + α)
(1+ β)
β
Ans : 4
Q15. In practice, the voltage gain of an amplifier is expressed ……………..
As volts
As a number
In db
None of the above
Ans : 3
16. If the power and current gains of a transistor amplifier are 16500 and 100 respectively, then voltage gain is ………
165
165 x 104
100
None of the above
Ans : 1
17. If RC and RL represent the collector resistance and load resistance respectively in a single stage transistor amplifier, then a.c. load is ……..
RL + RC
RC || RL
RL – RC
RC
Ans : 2
18. In a CE amplifier, the phase difference between voltage across collector load RC and signal voltage is ………..
180o
270o
90o
0o
Ans : 4
19. In the a.c. equivalent circuit of a transistor amplifier, the capacitors are considered ………….
Short
Open
Partially open
None of the above
Ans : 1
20. In a single stage transistor amplifier, RC and RL represent collector resistance and load resistance respectively. The transistor sees a d.c. load of ………..
RC + RL
RC || RL
RL
RC
Ans : 4
21. The purpose of d.c. conditions in a transistor is to …………..
Reverse bias the emitter
Forward bias the collector
Set up operating point
None of the above
Ans : 3
22. An amplifier has a power gain of 100. Its db gain is ……………
10 db
20 db
40 db
None of the above
Ans : 2
23. In order to get more voltage gain from a transistor amplifier, the transistor used should have …………..
Thin base
Thin collector
Wide emitter
None of the above
Ans : 1
24. The purpose of a coupling capacitor in a transistor amplifier is to ……….
Increase the output impedance of transistor
Protect the transistor
Pass a.c. and block d.c.
Provide biasing
Ans : 3
25. The purpose of emitter capacitor (i.e. capacitor across RE) is to ……….
Avoid voltage gain drop
Forward bias the emitter
Reduce noise in the amplifier
None of the above
Ans : 1
26. The ratio of output impedance of a CE amplifier is ……………
About 1
Low
High
Moderate
Ans : 4
27. If a transistor amplifier feeds a load of low resistance (e.g. speaker), then voltage gain will be ………….
High
Very high
Moderate
Low
Ans : 4
28. If the input capacitor of a transistor amplifier is short-circuited, then………
Transistor will be destroyed
Biasing conditions will change
Signal will not reach the base
None of the above
Ans : 2
29. The radio wave picked up by the receiving antenna is amplified about …….. times to have reasonable sound output
1000
A million
100
10000
Ans : 2
30. A CE amplifier is also called ………….. circuit
Grounded emitter
Grounded base
Grounded collector
None of the above
Ans : 1
31. The d.c. load of a transistor amplifier is generally ………….. that of a a.c. load
The same as
Less than
More than
None of the above
Ans : 3
32. The value of collector load RC in a transistor amplifier is ………… the output impedance of the transistor.
The same as
Less than
More than
None of the above
Ans : 2
33. A single stage transistor amplifier with collector load RC and emitter resistance RE has a d.c. load of ……….
RC
RC || RE
RC – RE
RC + RE
Ans : 4
34. In transistor amplifiers, we generally use ………….. capacitors.
Electrolytic
Mica
Paper
Air
Ans : 1
35. A single stage transistor amplifier with no load sees an a.c. load of ……..
RC + RE
RC
RC || RE
RC/RE
Ans : 2
36. The output power of a transistor amplifier is more than the input power because the additional power is supplied by …………
Transistor
Biasing circuit
Collector supply VCC
None of the above
Ans : 3
37. A transistor converts ……………
c. power into a.c. power
c. power into d.c. power
high resistance into low resistance
none of the above
Ans : 1
38. A transistor amplifier has high output impedance because ………..
Emitter is heavily doped
Collector has reverse bias
Collector is wider than emitter or base
None of the above
Ans : 2
39. For highest power gain, one would use …………….. configuration
CC
CB
CE
none of the above
Ans : 3
40. CC configuration is used for impedance matching because its ……………..
Input impedance is very high
Input impedance is low
Output impedance is very low
None of the above
Ans : 1