Question

Current in a circuit falls from $5.0$A to $0.0$A in $0.1$S. If an average emf of $200$V induced, given an estimate of the self-inductance of the circuit.

• A. $4$H
• B. $40$H
• C. $0.4$H
• D. $0.04$H

Answer 1

The correct option is A $4$H

Change in current $dI=5-0=5$A

$dt=0.1$s

$E_{av}=200$V

$e=L\frac{dI}{dt}$

$\therefore 200=L\left(\frac{5}{0.1}\right)$

$\Rightarrow L=\frac{200}{50}=4$H