Question

A virtual current of `4A` and `50Hz` flows in an `AC` circuit contaning a coil. The power consumed in the coil is `100V` its inductance will be
A. `1/(3pi) H`
B. `1/(5pi) H`
C. `1/(7pi) H`
D. `1/(9pi) H`

Answer 1

Correct Answer - B
`R=P/(i_(rms)^(2))=240/16=15 Omega`
`Z=V/i=100/4=25 Omega`
Now `X_(L)=sqrt(Z^(2)-R^(2))=sqrt((25)^(2)-(15)^(2))=20 Omega`
`:. 2pi vL =20 implies L =20/(2pixx50)=1/(5pi)Hz`