Question

an alternating voltage E=Eo sinwt is applied to a circuit containing a resistor R connected in series with a black box . The current in the circuit is found to be I=Io sinwt state whether the element in theblack box is capacitor or inductor

Answer 1

This circuit is a RLC circuit .

This means that the element in the black box consists of series of inductor and capacitor .

This RLC circuit is in resonance . This means that the inductive and capacitive reactances are equal in magnitude but cancel each other because they are 180 degrees apart in phase .

As, the current and voltage are in phase with each other so , RLC circuit is in resonance .

So, the only resistance is due to the resistor .