Electronics and Communication Engineering - Power Electronics

36. 

A single phase half wave converter is feeding a resistive load. Output dc power is Pdc and total power delivered to load is Pac then

A. Pdc = Pac for all values of firing angles
B. Pdc = Pac if firing angle is less than 180°
C. Pdc < Pac for all values of firing angles
D. Pdc < Pac if firing angle is less than 180°

Answer: Option D

Explanation:

No answer description available for this question. Let us discuss.

37. 

Which of the following devices exhibit negative resistance characteristics?

A. UJT
B. PUT
C. Both UJT and PUT
D. UJT, PUT and SBS

Answer: Option C

Explanation:

No answer description available for this question. Let us discuss.

38. 

In integral cycle control of ac regulators, the period of integral cycle control, i.e., (m + n) T should be

A. less than mechanical or thermal time constant of the system
B. more than the mechanical or thermal time constant of the system
C. more or less than the mechanical or thermal time constant
D. very high

Answer: Option A

Explanation:

No answer description available for this question. Let us discuss.

39. 

All other parameters remaining the same, a 3 phase bridge inverter with 180° mode of operation

A. has the same peak thyristor current as in 120° mode of operation
B. has higher peak thyristor current than in 120° mode of operation
C. has lower peak thyristor current than in 120° mode of operation
D. any of the above

Answer: Option B

Explanation:

No answer description available for this question. Let us discuss.

40. 

As compared to BJT, MOSFET has

A. lower switching losses and higher conduction losses
B. higher switching losses and higher conduction losses
C. higher switching losses and lower conduction losses
D. lower switching losses and lower conduction losses

Answer: Option A

Explanation:

No answer description available for this question. Let us discuss.