Question

In a black box of unknown elements (L or R or any other combination), an ac voltage `E=E_(0) sin (omegat)+phi)` is applied and current in the circuit was found to be `I=(I_0) sin [ omega t + phi + (pi//4)]`. Then the unknown elements in the box may be

A. only capacitor
B. both inductor and resistor
C. either capacitor, resistor and inductor or only capacitor and resistor
D. only resistor

Answer 1

Correct Answer - 3
Here current leads the voltage. So, there is reactance which is capacitive
`implies X = X_(C ) - X_(L)` or `X = X_(C )` alone besides `R`