Question

In a coil current falls from 5 A to 0 A in 0.2 s. If an average emf of 150 V is induced, then the self inductance of the coil is then

• A. 4 H
• B. 2 H
• C. 3 H
• D. 6 H

Answer 1

The correct option is D 6 H

Here,

$\frac{dI}{dt}=\frac{0-5}{0.2}=-25A{s}^{-1},\epsilon =150V$

As $\left|\epsilon \right|=L\left|\frac{dl}{dt}\right|$

$\therefore L=\frac{\left|\epsilon \right|}{\left|dI/dt\right|}=\frac{150}{25}=6H$