Top 250+ Solved Power Electronics MCQ Questions Answer
Q. In a series inverter
a. the commutating elements L and C are in parallel
b. the commutating elements L and C are in series with load
c. the commutating L and C may be in series or parallel with the load
d. none of the above
Q. In thermal ohm's law, temperature and power loss are analogous to
a. V and I respectively of ohm's law
b. I and V respectively of ohm's law
c. R and V respectively of ohm's law
d. I and R respectively of ohm's law
Q. A string of series connected thyristors needs equalising circuit to
a. ensure proper firing
b. ensure proper current division
c. ensure proper voltage division
d. none of the above
Q. The minimum gate current which can turn on SCR is called :
a. trigger current
b. holding current
c. junction current
d. breakover current
Q. A 3 phase dual converter consists of
a. two 3 phase semiconverters connected in parallel
b. two 3 phase semiconverters connected in antiparallel
c. two 3 phase full converters connected in antiparallel
d. two 3 phase full converters connected in parallel
Q. Which inverter circuit uses coupled inductors?
a. Modified McMurray full bridge inverter
b. McMurray Bedford half bridge inverter
c. Modified McMurray Bedford half bridge inverter
d. Both (b) and (c)
Q. When an SCR is in forward blocking mode, the applied voltage
a. appears across only one junction
b. is equally shared by two junctions
c. is equally shared by three junctions
d. may appear across one or more junctions
Q. In sinusoidal PWM for inverters the width of different pulses are notthe same.
a. True
b. False
c. none
d. all
Q. Mc Murray full bridge inverter uses
a. 4 thyristors and 2 diodes
b. 4 thyristors and 4 diodes
c. 8 thyristors and 4 diodes
d. 8 thyristors and 8 diodes
Q. In a 3 phase full converter, the instantaneous output voltage canhave negative part if
a. firing angle is less than 60°
b. firing angle is less than 90°
c. firing angle is more than 60°
d. firing angle is more than 90°
Q. The circuit in figure is for
a. resonant commutation
b. line commutation
c. auxiliary commutation
d. complementary commutation
Q. The main utility of SCR is due to
a. gate triggering
b. high temperature triggering
c. triggering
d. high breakdown voltage