Power electronics MCQ #12


1) Avalanche breakdown is primarily dependent on the phenomenon of
      (a) doping
      (b) collision
      (c) recombination
      (d) ionization

2) Which is the most suitable power electronics device for high frequency switching application? (>100kHz)
      (a) Microwave transistor
      (b) Schottky diode
      (c) BJT
      (d) Power MOSFET

3) Thyristor is similar as
      (a) an amplifier with large current rating.
      (b) an amplifier with higher gain.
      (c) a controlled switch.
      (d) a controlled transistor.

4) In a conducting SCR, the anode current is 10 A.  If the gate current is made half, then what will be the value of anode current?
      (a) 5 A
      (b) 20 A
      (c) 2 A
      (d) 10 A



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

5) If the supply voltage exceeds the break over voltage of SCR with open GATE, then SCR will conduct. This statement is
      (a) false.
      (b) true for DC only.
      (c) true.
      (d) true for AC only.

6) To provide dynamic voltage regulation, Static VAR controller are used. These controllers are primarily of
      (a) thyristor controlled capacitors.
      (b) thyristor switched inductors.
      (c) thyristor switched resistor.
      (d) thyristor controlled inductor and thyristor switched capacitor.
7) Which state is true for TRIAC.
      (a) TRIAC is a three terminal unilateral switch.
      (b) TRIAC is a two terminal bilateral switch
      (c) TRIAC is a three terminal bidirectional switch.
      (d) TRIAC is a two terminal switch.

8) UJT is known as
      (a) current controlled device.
      (b) voltage controlled device.
      (c) relaxation oscillator.
      (d) none of the above.



ANSWER: | 5-b | 6-d | 7-c | 8-b |

9) Which device can turn ON and turn OFF by gate signal?
      (a) SCR
      (b) SCS
      (c) TRIAC
      (d) UJT

10) The RMS value of half wave rectified symmetrical square wave current of 2A is
      (a) 1.41 A
      (b) 1 A
      (c) 1/1.41 A
      (d) 1.73 A

11) The purpose of feedback transformer and diode in complementary commutated inverter is to
      (a) improve the input power factor.
      (b) absorb more reactive power from source.
      (c) improve the power factor of the load.
      (d) return the trapped energy to source.

12) The output quality of ac voltage in a cycloconverter is improved by
      (a) decrease in output voltage at increase frequency.
      (b) decrease in output voltage at reduced frequency.
      (c) increase in output voltage at increased frequency.
      (d) increase in output voltage at reduced frequency.


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


Power electronics #2
Power electronics #3
Power electronics #4
Power electronics #5
Power electronics #6
Power electronics #7
Power electronics #8
Power electronics #9
Power electronics #10
Power electronics #11

To download this MCQ as PDF click on below link,

Power electronics MCQ PDF #12

No comments

Powered by Blogger.