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` 5.6, A
C. 40 4. `Omega` 5, A
D. 50 `Omega` 4, A

Answer

D

Explanation

` Z = sqrt(R^(2) + (omega L)^(2)) = sqrt( 30^(2) + ( 2 pi xx 50 xx (0.4)/(pi))^(2))`
` = sqrt(30^(2) + 40^(2)) = 50 Omega `
Current ` i = (V)/(Z) = (200)/(50) = 4 A `