BASICS ON TRANSISTOR BIASING
1. Transistor biasing represents ……………. conditions
1. a.c.
2. d.c.
3. both a.c. and d.c.
4. 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
