The energy stored in a $50 \, mH$ inductor carrying a current of $4 \, A$ will be $J$.

Two circuits $A$ and $B$ are connected to identical d.c. sources each of e.m.f. $10 \ V$. Self-inductances of circuits $A$ and $B$ are respectively $L_A = 10 \ H$ and $L_B = 10 \ mH$. The total resistance of each circuit is $40 \ \Omega$. The ratio of energy consumed in circuit $A$ and circuit $B$ to build up the current to steady value is

If the current in a coil is halved,then the energy stored becomes how many times the previous value?

In the figure, the magnetic energy stored in the coil is:

Assertion : If the current in a solenoid is reversed in direction while keeping the same magnitude,the magnetic field energy stored in the solenoid remains unchanged.
Reason : Magnetic field energy density is proportional to the magnetic field.

Define an inductor. Derive the equation for the energy $U = \frac{1}{2}LI^2$ stored in an inductor.