A coil has an inductance of $5\;H$ and resistance $20\; \Omega$ . An emf of $100\; v$ is applied to it. What is the energy stored in the magnetic field, when the current has reached its final value .

Question

$\begin{array}{1 1} 100\;J \\ 125\;J \\ 200\;J \\ 225\;J \end{array} $