The time constant of a series RL circuit (τ) is given by

A)
RC
B)
R/L
C)
L/R
D)
1/RL

Correct Answer : Option (B) :   R/L

Explanation : The time constant τ for a series RL circuit is R/L.

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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