Transistor biasing Objective questions MCQ with answer

Transistor biasing MCQ with answer

Objective questions Transistor biasing MCQ

1. Transistor biasing is done to keep ……… in the Circuit

1. Proper direct current
2.  proper alternating current
3.  the base current small
4.  collector current small

2. Operating point represents :

1. Values of I_C \; and \; V_{CE} when signal is applied
2. The magnitude of the signal
3.  zero signal values of I_C\; and \; V_{CE} 
4.  none of the above

3. The potential divider biasing is used in the Amplifier to :

1. Make the operating point almost independent of β
2. Reduce the DC base current
3. Reduce the cost of the circuit
4. Limit the input ac signal going to the base

4. The q-point in a voltage amplifier is selected in the middle of the active region because :

1. it gives the better stability
2. The circuit needs a small DC voltage
3. The Biasing circuits then needs less number of resistors
4. It gives a distortion less output

5. Thermal Runaway occurs when

1. Collector is Reverse biased
2. Transistor is not biased
3.  emitter is forward biased 
4. Junction capacitance is high

6. The base resistor method is generally used in 

1. Amplifier current
2.  switching current
3.  rectifier current
4.  none of these

7. The stability factor of the collector feedback bias Circuit is ……… is that of base resistor bias

1. The same as
2.  more than
3.  less than
4.  none of these

8. When temperature changes the operating point is shifted due to

1. Change in I{cbo}
2.  change in V_{cc}
3.  change in the value of circuit resistances 
4. None of these

9. The value of stability factor for the base resistor bias is 

1.   R_B(β+1)
2.  (β+1)R_C 
3. (β+1)
4. (β-1)

10. If the temperature increases, the value of  V_{BE} 

1. Remains the same
2.  is increased
3.  is decreased
4.  none of these

11. The potential divider or Universal bias circuit is mostly used because:

1. Collector current does not depend on transistor parameters 
2. Collector current equals the emitter current
3. Its stability factor is high
4. Its β -Sensitivity is high

12. The DC load line of a transistor:

1. Has a negative slope
2.  is a curved line
3.  does not contain the Q point
4.  none of these

13. For linear magnification, the DC operating point on a characteristic curve should be :

1. Near the cut off voltage
2.  anywhere at the collector load line
3.  in between the cutoff and saturation regions
4.  near the saturation regions

14. In common base PNP transistor amplifier, power gain is :

1.  A_vA_i
2.   \frac{A_v} {A_i}
3. \frac{A_i} {A_v}
4. None of these.

15. The knee voltage for Si-transistor is :

1. 0.3 volt
2.  0.5 volt
3.  0.7 volt
4.  1 volt

16. Voltage gain of two stage RC  coupled amplifier is 150, if the voltage gain of the first stage is 15, the voltage gain of second stage is :

1. 105
2.  10
3.  1800
4.  8 

17. If two stages of a cascaded amplifier Have decimal gains 60 and 30 respectively. then overall gain in DB is :

1. 1800
2.  90
3.  2
4.  ½ 

18. The DB gain of a cascaded amplifier equals the :

1. Product of individual gains
2. Sum of individual gains
3.  ratio of individual gains
4.  sum of voltage and current gains

19. Multistage amplifier are used in order to achieve :

1. Greater voltage gain
2.  greater power gain
3.  greater frequency response
4.  all of these

20. In a RC coupled amplifier, the coupling condenser:

1. Passes only the DC component of output of first stage to input of 2nd stage
2. Passes only ac component of output of first stage to input of 2nd stage
3. Both a and b
4. None of these

21. In a RC coupled amplifier, the transistor are used in in

1.  CB mode
2.  CE mode
3.  CC mode
4. All of these

22. Transistor biasing is generally provided by :

1. Biasing circuit
2.  biasing battery
3.  diode
4.  None. 

23. An idea value of stability factor is :

1. 1
2.  2
3.  3
4.  None

24. A graph between voltage gain and frequency is known as :

1. Ripple factor
2. Bandwidth
3. Curve
4. Frequency resonance

25. The intersection point of DC and AC load line is known as :

1. Single point
2. Joint
3.  operating point
4.  None 

Answers

1. (1)
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8. (1)
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11. (1)
12. (1)
13. (3)
14. (1)
15. (4)
16. (2)
17. (2)
18. (2)
19. (4)
20. (1)
21. (2)
22. (1)
23. (1)
24. (4)
25. (3)