Question

The average power dissipated in AC circuit is 2W. If a current flowing throuh a circuit is 2A, impedance is `1Omega`, then what is the power factor of the circuit?
A. `0.5`
B. 1
C. Zero
D. `1/sqrt(2)`

Answer 1

Correct Answer - A
As a average power, `hatP= 2W, I_(rms) = 2A`, ltbrltgt Impedance, `Z=1Omega`
Power factor `(cosphi)`=?
We know that, `barP = V_(rms) xx I_(rms) xx cos phi`
`rArr barP= I_(rms)^(2)Z.cosphi`
`cosphi= barP/(I_(rms)^(2)Z) = 2/(2^(2)xx1)=2/4 =1/2=0.5`