If resistance is 20 ohms. and inductance is 27 in a R-L series circuit, then time constant of this circuit will be
A. 0.001 s
B. 0.1 s
C. 10 s
D. 100 s
Answer: Option B
This Question Belongs to Electrical Engineering >> A.C Fundamentals, Circuits And Circuit Theory
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Comments ( 3 )
Which of the following refers to a parallel circuit?
A. The current through each element is same
B. The voltage across element is in proportion to it's resistance value
C. The equivalent resistance is greater than any one of the resistors
D. The current through any one element is less than the source current
A. Apparent power is more than actual power
B. Reactive power is more than apparent power
C. Actual power is more than reactive power
D. Reactive power is more than actual power
The transient currents are associated with the
A. Changes in the stored energy in the inductors and capacitors
B. Impedance of the circuit
C. Applied voltage to the circuit
D. Resistance of the circuit
The inductance of a coil can be increased by
A. Increasing core length
B. Decreasing the number of turns
C. Decreasing the diameter of the former
D. Choosing core material having high relative permeability
It's 2H not 27 now T=L/R
T=2/20=0.1s
I believe the question is wrong, it's not 20Q it's actually 200. And time constant for rl ckt is L/R ie 27/200 which gives us 0.135 and hence option B
Explanation