Question

When induced emf in inductor coil is $50$ of its maximum value then stored energy in inductor coil in the given circuit will be-

• A. $2.5mJ$
• B. $5mJ$
• C. $15mJ$
• D. $20J$

Answer 1

The correct option is A $2.5mJ$

For max. induced emf across inductor will be at $t=0$, when it will behave as O.C.
$V=2v=V_{max}$ ($\coprod$el circuit Voltage will be same)
$50$ of its max. That means $1$ volt.
When voltage of $1$ volt appears across inductor
Then, $2=1\times i+1$
$[I=1Amp]$
Energy stored in inductor $=\frac{1}{2}L{i}^2$

$=\frac{1}{2}\times 5\times 1^2\times {10}^{-3}$

$E=2.5mJ$