BJT Quiz

1. N-P-N transistor Acts as switch in following

A. Uncontrolled rectifier
B. HF signal amplifier
C. Large current amplifier
D. Digital logic gates

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D. Digital logic gates

2. The switching time of N-P-N transistors is in the range of

A. Few nanosecond
B. Few millisecond
C. Few microsecond
D. Few picosecond

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D. Few picosecond

3. In a PNP transistor biased in the active region, the dominant carrier flow is

A. Minority carriers diffusing in the emitter region
B. Minority carriers electrons injected from base to emitter
C. Excess holes drifting in the base region
D. Due to concentration gradients of holes, holes diffusing in the base region

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D. Due to concentration gradients of holes, holes diffusing in the base region

4. Which of the following BJT configuration is most widely used ?

A. CB
B. CE
C. CC
D. None of the above

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B. CE

5. For P-N-P transistor to be operated as closed switch

A. Q-Point should be in cut-off
B. Q-Point should be in saturation
C. Q-Point should be in beyond cut-off
D. Q-Point should be in semi active region

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B. Q-Point should be in saturation

6. Which of the following configuration is used as a input stage?

A. CB
B. CE
C. CC
D. None of the above

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A. CB

7. The following factors affect the Q point stability in N-P-N transistor amplifier

A. Beta
B. Temperature
C. Beta and temperature
D. Junction capacitance

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C. Beta and temperature

8. The base current in the PNP transistor flows due to

A. Mobile Ions beyond depletion layer
B. Immobile Ions in depletion layer
C. Ambient temperature
D. Electron-hole recombination

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D. Electron-hole recombination

9. In a PNP transistor in the active region of operation the base current is due to

A. Holes injected into the emitter from base
B. Holes entering the base from the terminal for recombination
C. Only saturation current due to reverse bias of collector junction
D. Electrons recombining with a part of the holes diffusing in the base region

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D. Electrons recombining with a part of the holes diffusing in the base region

10. The P-N-P transistor turn-off time should be

A. Large
B. Medium
C. Short
D. None of above

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C. Short