Power Electronics MCQ #17

1) The middle region of transistor is called _____.

      (a) Emitter

      (b) Base

      (c) Collector

      (d) diffusion

2) When the PN junction diode is under forward biased condition, increasing the battery voltage is results ________.

      (a) the current through PN junction remains constant.

      (b) the current flow through the junction is zero.

      (c) the current through PN junction is decreased.

      (d) increasing the current through PN junction.

3) In half wave rectifier, ______ number of diode/s needed.

      (a) one

      (b) two

      (c) eight

      (d) four

4) Which of the following material has a resistance between the insulator and conductor?

      (a) conductors

      (b) insulators

      (c) semiconductor materials

      (d) none of the above

ANSWER: | 1-b | 2-d | 3-a | 4-c |

5) Purest form of the semiconductor form is known as______.

      (a) extrinsic semiconductors

      (b) intrinsic semiconductors

      (c) combinations of A and B

      (d) trivalent substance

6) By adding impurity, the conductivity of semiconductor increased is known as _____.

      (a) doping

      (b) increase energy gap

      (c) increase forbidden gap

      (d) reduced energy gap

7) The doped semiconductors are known as ______.

      (a) electrons majority carries

      (b) extrinsic semiconductor

      (c) intrinsic semiconductor

      (d) holes majority carries

8) In intrinsic semiconductor, the number of holes is ______.

      (a) equal to number of electrons

      (b) greater than number electrons

      (c) less than number electrons

      (d) none of the above

ANSWER: | 5-b | 6-a | 7-b | 8-a |

9) The forbidden energy gap of silicon is ____and for germanium is ____.

      (a) 1.1 eV; 1.1 eV

      (b) 0.72 eV; 1.1 eV

      (c) 0.72 eV; 0.72 eV

      (d) 1.1 eV; 0.72 eV

10) In semiconductor, the highest filled band is known as _____ band.

      (a) forbidden gap

      (b) conduction

      (c) valance

      (d) none of the above

11) By which region the conduction band and valence band are separated?

      (a) forbidden energy gap

      (b) conduction band

      (c) valance band

      (d) none of the above

12) Which of the following band has highest energy level?

      (a) forbidden energy band

      (b) valance band

      (c) energy band

      (d) conduction band

ANSWER: | 9-d | 10-c | 11-a | 12-d |