Top 250+ Solved Power Electronics MCQ Questions Answer
Q. In a full bridge inverter, the waveshape of load current depends on
a. relative values of load parameters R, L and C
b. relative values of load parameters R and L
c. relative values of load parameters L and C
d. gating frequency
Q. The characteristics of which device has peak point and valley point
a. SCR
b. PUT
c. SCS
d. Shockley diode
Q. In an ordinary thyristor
a. turn on and turn off times are equal
b. turn on time is more than turn off time
c. turn off time is more than turn on time
d. turn on time may be equal, less than or more than turn off time
Q. Thyristors connected in series need :
a. static equalizing circuit
b. dynamic equalizing circuit
c. both static and dynamic equalizing circuits
d. none of the above
Q. If 4 quadrant operation is required we need
a. dual converter
b. full converter
c. semi converter
d. none of the above
Q. Which of the following devices exhibit negative resistance characteristics?
a. UJT
b. PUT
c. Both UJT and PUT
d. UJT, PUT and SBS
Q. 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
Q. In the basic series inverter circuit, the source supplies load
a. only in positive half cycle
b. both in positive and negative half cycles
c. only in part of positive half cycle
d. in positive half cycle and part of negative half cycle
Q. In a parallel inverter
a. each thyristor is turned on twice during each cycle
b. each thyristor is turned on once during each cycle
c. each thyristor is turned on either once or twice in each load cycle
d. each thyristor may be turned on upto four times in each load cycle
Q. The specified maximum junction temperature of thyristors is about
a. 50°C
b. 80°C
c. 120°C
d. 200°C
Q. A half bridge inverter
a. needs a 3 wire dc supply
b. may use a two wire or 3 wire dc supply
c. has higher output voltage if fed from 3 wire dc supply
d. has higher efficiency if fed from 3 wire dc supply
Q. A 3 phase series inverter has
a. 12 thyristors
b. 6 thyristors
c. 3 thyristors
d. 3 or 6 thyristors
Q. Surge current rating of an SCR is
a. the maximum repetitive surge current in which the SCR can withstand
b. the maximum non-repetitive surge current in which the SCR can withstand
c. the maximum repetitive or non repetitive surge current in which the SCR can withstand
d. the maximum surge current in which the SCR can withstand if both surge current and steady current exist together
Q. Which of the following devices has metal-silicon junction?
a. General purpose power diode
b. Schottky diode
c. SCR
d. MOSFET