Power Electronics MCQs

Power Electronics combines the solid-state electronic components with control and power systems so as to control the electric power systems, drives, and industrial controls. While modern switchyards and substations heavily rely on power electronics, it is crucial to develop a clear image of the entire subject. In this regard, Electrical Engineering XYZ shares power electronics MCQs which are important for electrical jobs, competitive tests, university exams.

1. The device which performs dc-dc conversion:

  1. Inverter
  2. Rectifier
  3. Chopper
  4. Switch

Correct answer: c. Chopper

Explanation: Chopper is an electrical device which converts dc to dc.

2. The DIAC is a:

  1. One terminal device
  2. Two terminal device
  3. Three-terminal device
  4. Four terminal device

Correct answer: b. Two terminal device

3. The TRIAC is:

  1. An SCR
  2. Made up of three DIAC’s
  3. Is alike a bi-directional SCR
  4. None of these

Correct answer: c. Is alike a bi-directional SCR

The structure of TRIAC matches two SCR’s which are joined back to back in a parallel fashion. Thus we can relate a TRIAC with a bi-directional SCR.

4. A thyristor has:

  1. One pn junction
  2. Two pn junctions
  3. Three pn junctions
  4. Four pn junctions

Correct answer: c. Three pn junctions

5. The SCS has:

  1. Single gate terminal
  2. Two gate terminals
  3. Three gate terminals
  4. Four gate terminals

Correct answer: b. Two gate terminals

6. Forced commutation on SCS can be achieved by:

  1. Shorting anode and cathode terminals
  2. By Applying a negative voltage between anode and cathode
  3. Both of these
  4. None of these

Correct answer: c. Both of these

7. The correct statement about SCR:

  1. SCR is not a rectifier
  2. A single SCR can’t be used in full ac control
  3. SCR is not used commonly because it is very expensive
  4. GTO is a variant of SCR

Correct answer: b. A single SCR can’t be used in full ac control

8. PUT stands for:

  1. Programmable Unijunction Transistor
  2. Positive Unijunction Transistor
  3. Photoconductive Unijunction Transistor
  4. Pi Unijunction Transistor

Correct answer: a. Programmable Unijunction Transistor

9. A DIAC conducts current in:

  1. One direction
  2. Two directions

Correct answer: b. Two directions

10. The LASCR is:

  1. A laser activated SCR
  2. A light-activated SCR
  3. Lithium anode SCR
  4. None of these

Correct answer: b. A light-activated SCR

11. Sort the correct statement about DIAC and TRIAC:

  1. Both are bilateral devices
  2. TRIAC is bilateral, but DIAC is unilateral
  3. DIAC is bilateral, but TRIAC is unilateral
  4. Both are unilateral devices

Correct answer: a. Both are bilateral devices

12. Which one the following is not a thyristor:

  1. SCS
  2. UJT
  3. DIAC
  4. TRIAC

Correct answer: b. UJT

13. The device which performs dc-ac conversion:

  1. Inverter
  2. Rectifier
  3. Chopper
  4. Switch

Correct answer: a. Inverter

14. The SCS is a _____ terminal thyristor that has _____ gate terminals.

  1. Two, two
  2. Two, four
  3. Four, two
  4. Four, one

Correct answer: c. Four, two

15. The SCS is turned on by:

  1. Applying a negative pulse on anode gate
  2. Applying a positive pulse on anode gate
  3. Applying a negative pulse on cathode gate
  4. None of these

Correct answer: a. Applying a negative pulse on anode gate

16. UJT has ______ pn junction/junctions:

  1. Single
  2. Two
  3. Three
  4. Four

Correct answer: 1. Single

17. Which one of the following is not a thyristor:

  1. PUT
  2. UJT
  3. SCS
  4. DIAC

Correct answer: b. UJT

18. LASCR is a:

  1. Rectifier
  2. Thyristor
  3. Both of these
  4. None of these

Correct answer: 3. Both of these

19. ______ has/have no gate terminal:

  1. Diac
  2. Triac
  3. Both of these
  4. None of these

Correct answer: a. Diac

20. The method which can be used to latch Shockley diode:

  1. Exceed the critical rate of voltage rise from anode to cathode
  2. Exceed the breakover voltage from anode to cathode
  3. Both of these
  4. None of these

Correct answer: 3. Both of these

One thought on “Power Electronics MCQs

  • January 5, 2018 at 5:26 am
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    Dear sir,
    Notify me when new material uploaded and send me old material.

    Thank you,

    Reply

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