In a `L-R` circuit, the value of `L` is `(0.4/(pi))` henry and the value of `R` is `30` ohm. If in the circuit, an alternating e.m.f of `200` vol at `50` cycles per sec is connected, the impendence of the circuit will be

Options

A. `11.4 Omega, 17.5 A`
B. `30.7 Omega, 6.5 A`
C. `40.7 Omega, 5 A`
D. `50 Omega,4A`

Answer

D

Explanation

`Z=sqrt(R^(2)+X^(2))=sqrt(R^(2)+(2pifL)^(2))`
`=sqrt((30)^(2)+(2pixx50xx0.4/(pi))^(2)) =sqrt(900+1600)=50Omega`
`i=V/Z=200/500=4` ampere