The class A commutation or load commutation is possible in case of

A)
dc circuits only
B)
ac circuits only
C)
Both DC and AC circuits
D)
None of the above

Correct Answer : Option (A) :   dc circuits only

Explanation : The nature of the circuit should be such that when energized from the source, current must a a natural tendency to decay to zero for load commutation to occur in a SCR circuit.

Recently Updated in Power Electronics Questions
Static UPS requires ______
A)
only rectifier
B)
only inverter
C)
both inverter and rectifier
D)
None of the above

Correct Answer :   both inverter and rectifier

Explanation : Rectifier to converter the dc from the battery to ac. Inverter to charge the battery from mains.

HVDC transmission has ___________ as compared to HVAC transmission.
A)
higher corona loss
B)
smaller transformer size
C)
smaller power transfer capabilities
D)
smaller conductor size

Correct Answer :   smaller conductor size

Explanation : The conductor size is smaller as there is no sink effect, and the whole conductor is utilized for transmitting power.

SPMS are based on the ________ principle.
A)
MOSFET
B)
Chopper
C)
Phase control
D)
Integral control

Correct Answer :   Chopper

Explanation : SMPS (Switching mode power supply) are based on the chopper principle. The output dc voltage is controlled by varying the duty cycle of the chopper circuit.

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