Question

A coil of resistance $5\Omega$ and inductance $4H$ is connected to a $10V$ battery. The energy stored in the coil

• A. $0.8J$
• B. $8J$
• C. $16J$
• D. $4J$

Answer 1

The correct option is B $8J$

Initially, the inductor will oppose the flow of current but eventually the current in the circuit will be $i=\frac{V}{R}$ where V is voltage of the battery and R is the resistance.
Energy stored in the inductor L : $U=\frac{1}{2}L{i}^2=\frac{1}{2}\times 4\times {\left(\frac{10}{5}\right)}^2=8J$