Question

When current in a coil changes from $5 \,A$ to $2 \,A$ in $0.1\, s$, an average voltage of $50\, V$ is produced. The self - inductance of the coil is :

• A. 0.67 H
• B. 1.67 H
• C. 3 H
• D. 6 H

Answer 1

Answer: (B)

1.67 H

Answer 2

According to Faraday?s law of electromagnetic induction,
Induced emf, $e =\frac{Ldi}{dt}$
$50 = L\left(\frac{5-2}{0.1\,sec}\right)$
$\Rightarrow L = \frac{50\times0.1}{3} = \frac{5}{3} = 1.67\, H$