Question

An alternating e.m.f. of 200V,50Hz is applied to a series L-R circuit. If `L=(0.4)/(pi)` henry and `R=30 Omega`, then the impendance of the circuit and the current in the circuit will be
A. `35 Omega, 8A`
B. `15 Omega, 10A`
C. `50 Omega, 4A`
D. `37.5 Omega, 6.5A`

Answer 1

Correct Answer - C
`Z = sqrt(R^(2)+L^(2)omega^(2)) = sqrt(R^(2)+4 pi^(2)f^(2)L^(2))`
`sqrt(30^(2)+4 xx pi^(2) xx 2500 xx (0.16)/(pi^2)) = 50 Omega`
`:. I = 200/50 = 4 A`.