Question

Calculate the resistance in an RL circuit in which L " 2.50 H

and the current increases to 90.0% of its final value in

3.00 s.

Answer 1

Given

Inductance is $L=2.50 H$

Current after time 3.00 s is $I=0.90 I_0$

The current passing through the inductor after time t is

$I=I_0e^{-\frac{Rt}{L}}$

$0.90I_0=I_0e^{-\frac{R(3.00 s)}{2.50 H}}$

On solving the above equation, we get

$R=0.0878 \Omega$