Power Electronics(Electrical Engineering ) Questions and answers for exam Preparation

Question 1. The UJT may be used as ___________.

Am amplifier
A sawtooth generator
A rectifier
None of the above

Explanation:-

Answer: Option B. -> A sawtooth generator

Question 2. A diac has ___________ pn junctions

Four
Two
Three
None of the above

Explanation:-

Answer: Option B. -> Two

Question 3. A UJT has ___________.

Two pn junctions
One pn junction
Three pn junctions
None of the above

Explanation:-

Answer: Option B. -> One pn junction

Question 4. A diac has ___________ terminals.

Two
Three
Four
None of the above

Explanation:-

Answer: Option A. -> Two

Question 5. A triac is a ___________ switch

Bidirectional
Unidirectional
Mechanical
None of the above

Explanation:-

Answer: Option A. -> Bidirectional

Question 6. The normal way to turn on a diac is by ___________.

Gate current
Gate voltage
Breakover voltage
None of the above

Explanation:-

Answer: Option C. -> Breakover voltage

Question 7. A triac can pass a portion of ___________ half-cycle through the load.

Only positive
Only negative
Both positive and negative
None of the above

Explanation:-

Answer: Option C. -> Both positive and negative

Question 8. Which of the following is not a characteristic of UJT?

Intrinsic stand off ratio
Negative resistance
Peak-point voltage
Bilateral conduction

Explanation:-

Answer: Option D. -> Bilateral conduction

Question 9. After peak point, the UJT operates in the ___________ region.

Cut-off
Saturation
Negative resistance
None of the above

Explanation:-

Answer: Option C. -> Negative resistance

Question 10. Between the peak point and the valley point of UJT emitter characteristics we have ___________ region

Saturation
Negative resistance
Cut-off
None of the above

Explanation:-

Answer: Option B. -> Negative resistance