Power Electronics MCQ #15

1) BJT has _____ operating region.
      a) 1
      b) 2
      c) 3
      d) 4

2) The BJT is supposed to work as an amplifier, the circuit is so designed to bias it in _______ of operation.
      a) Active region
      b) Cut-off region
      c) Saturation region
      d) None of the above

3) BJT will work in cutoff region when it is ______ and in saturation region when it is ______.
      a) OFF, OFF
      b) ON, OFF
      c) OFF, ON
      d) ON, ON

4) When the switch is _______, it has zero voltage drop across it and carries full current through it, and when it is in _______ condition.
      a) ON, OFF
      b) ON, ON
      c) OFF, OFF
      d) OFF, ON


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

5) When positive terminal of a voltage source is connected to the n-type region and the negative terminal of the source is connected to the p-type region then the pn junction is said to be in_______ condition.
      a) Forward biased
      b) Reverse biased
      c) Both forward and reverse biased
      d) Cannot predict

6) When there is no voltage applied across the p n junction, the potential developed across the junction is _______ volts at 25 C for germanium pn junction.
      a) 0.5
      b) 0.7
      c) 0.8
      d) 0.3

7) When there is no voltage applied across the p n junction, the potential developed across the junction is _______ volts at 25 C for silicon pn junction.
      a) 0.5
      b) 0.7
      c) 0.8
      d) 0.3

8) Saturation current in PN junction is ____ A.

      a) 10^-9 to 10^-18 A

      b) 10^-19 to 10^-28 A

      c) 10^-1 to 10^-8 A

      d) 10^-1 to 10^-2 A

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

9) The forward biased p-n junction resistance is rd ohm it is called _______.

      a) AC resistance

      b) Dynamic resistance

      c) DC resistance

      d) (a) and (b) both

10) The depletion layer ______ the transition capacitance of PN junction value goes down.

      a) decrease

      b) increase

      c) both

11) ________ is the time taken by the electrons to move from n-type region to p-type region and p-type region to n-type region.

      a) Storage Time

      b) Transition Time

      c) Reverse Recovery Time

      d) Fall time

12) ________ is sum of the storage time and transition time.

      a) Storage Time

      b) Transition Time

      c) Reverse Recovery Time

      d) Fall time

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