TRANSISTOR BIASING Questions and Answers pdf :-
1. Transistor biasing represents ……………. conditions
- a.c.
- d.c.
- both a.c. and d.c.
- none of the above
Ans : 2
2. Transistor biasing is done to keep ………… in the circuit
Proper direct current
Proper alternating current
The base current small
Collector current small
Ans : 1
3. Operating point represents …………..
Values of IC and VCE when signal is applied
The magnitude of signal
Zero signal values of IC and VCE
None of the above
Ans : 3
4. If biasing is not done in an amplifier circuit, it results in ……………
Decrease in the base current
Unfaithful amplification
Excessive collector bias
None of the above
Ans : 2
5. Transistor biasing is generally provided by a …………….
Biasing circuit
Bias battery
Diode
None of the above
Ans : 1
6. For faithful amplification by a transistor circuit, the value of VBE should ………. for a silicon transistor
Be zero
Be 0.01 V
Not fall below 0.7 V
Be between 0 V and 0.1 V
Ans : 3
7. For proper operation of the transistor, its collector should have …………
Proper forward bias
Proper reverse bias
Very small size
None of the above
Ans : 2
8. For faithful amplification by a transistor circuit, the value of VCE should ……….. for silicon transistor
Not fall below 1 V
Be zero
Be 0.2 V
None of the above
Ans : 1
9. The circuit that provides the best stabilization of operating point is …………
Base resistor bias
Collector feedback bias
Potential divider bias
None of the above
Ans : 3
10. The point of intersection of d.c. and a.c. load lines represents …………..
Operating point
Current gain
Voltage gain
None of the above
Ans : 1
11. An ideal value of stability factor is …………..
100
200
More than 200
1
Ans : 4
12. The zero signal IC is generally ……………… mA in the initial stages of a transistor amplifier
4
1
3
More than 10
Ans : 2
13. If the maximum collector current due to signal alone is 3 mA, then zero signal collector current should be at least equal to ………..
6 mA
mA
3 mA
1 mA
Ans : 3
14. The disadvantage of base resistor method of transistor biasing is that it …………
Is complicated
Is sensitive to changes in ß
Provides high stability
None of the above
Ans : 2
15. The biasing circuit has a stability factor of 50. If due to temperature change, ICBO changes by 1 µA, then IC will change by …………
100 µA
25 µA
20 µA
50 µA
Ans : 4
16. For good stabilsation in voltage divider bias, the current I1 flowing through R1 and R2 should be equal to or greater than
10 IB
3 IB
2 IB
4 IB
Ans : 1
17. The leakage current in a silicon transistor is about ………… the leakage current in a germanium transistor
One hundredth
One tenth
One thousandth
One millionth
Ans : 3
18. The operating point is also called the ………….
Cut off point
Quiescent point
Saturation point
None of the above
Ans : 2
19. For proper amplification by a transistor circuit, the operating point should be located at the ………….. of the d.c. load line
The end point
Middle
The maximum current point
None of the above
Ans : 2
20. The operating point ………………… on the a.c. load line
Also line
Does not lie
May or may not lie
Data insufficient
Ans : 1
21. The disadvantage of voltage divider bias is that it has ………….
High stability factor
Low base current
Many resistors
None of the above
Ans : 3
22. Thermal runaway occurs when ……….
Collector is reverse biased
Transistor is not biased
Emitter is forward biased
Junction capacitance is high
Ans : 2
23. The purpose of resistance in the emitter circuit of a transistor amplifier is to ………….
Limit the maximum emitter current
Provide base-emitter bias
Limit the change in emitter current
None of the above
Ans : 3
24. In a transistor amplifier circuit VCE = VCB + ……………..
VBE
2VBE
5 VBE
None of the above
Ans : 1
25. The base resistor method is generally used in ………
Amplifier circuits
Switching circuits
Rectifier circuits
None of the above
Ans : 2
26. For germanium transistor amplifier, VCE should ………….. for faithful amplification
Be zero
Be 0.2 V
Not fall below 0.7 V
None of the above
Ans : 3
27. In a base resistor method, if the value of ß changes by 50, then collector current will change by a factor ………
25
50
100
200
Ans : 2
28. The stability factor of a collector feedback bias circuit is ……….. that of base resistor bias.
The same as
More than
Less than
None of the above
Ans : 3
29. In the design of a biasing circuit, the value of collector load RC is determined by …………
VCE consideration
VBE consideration
IB consideration
None of the above
Ans : 1
30. If the value of collector current IC increases, then the value of VCE …………
Remains the same
Decreases
Increases
None of the above
Ans : 2
31. If the temperature increases, the value of VCE …………
Remains the same
Is increased
Is decreased
None of the above
Ans : 3
32. The stabilisation of operating point in potential divider method is provided by ……….
RE consideration
RC consideration
VCC consideration
None of the above
Answer: 1
33. The value of VBE …………….
Depends upon IC to moderate extent
Is almost independent of IC
Is strongly dependant on IC
None of the above
Ans : 2
34. When the temperature changes, the operating point is shifted due to …….
Change in ICBO
Change in VCC
Change in the values of circuit resistance
None of the above
Ans : 1
35. The value of stability factor for a base resistor bias is …………
RB (ß+1)
(ß+1)RC
(ß+1)
1-ß
Ans : 3
36. In a particular biasing circuit, the value of RE is about ………
10 kO
1 MO
100 kO
800 O
Ans : 4
37. A silicon transistor is biased with base resistor method. If ß=100, VBE =0.7 V, zero signal collector current IC = 1 mA and VCC = 6V , what is the value of the base resistor RB?
105 kO
530 kO
315 kO
None of the above
Ans : 2
38. In voltage divider bias, VCC = 25 V; R1 = 10 kO; R2 = 2.2 V ; RC = 3.6 V and RE =1 kO. What is the emitter voltage?
7 V
3 V
V
8 V
Ans : 4
39. In the above question (Q38.) , what is the collector voltage?
3 V
8 V
6 V
7 V
Ans : 1
40. In voltage divider bias, operating point is 3 V, 2 mA. If VCC = 9 V, RC = 2.2 kO, what is the value of RE ?
2000 O
1400 O
800 O
1600 O
Ans : 3