$A$ solenoid of inductance $2 \ H$ carries a current of $1 \ A$. What is the magnetic energy stored in the solenoid (in $J$)?

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

When a current $I$ flows through a coil,it stores the energy $E_1$ in it. Now the current is reduced to $I/2$,the energy stored in the coil becomes $E_2$. The change in the energy is

If the current through an inductor increases from $2 \ A$ to $3 \ A$,the magnetic energy stored in the inductor increases by: (in $\%$)

The magnetic potential energy stored in a certain inductor is $64 \times 10^{-3} \ J$,when the current in the inductor is $80 \ mA$. The inductance of this inductor is: (in $H$)

$A$ coil with resistance $20\, \Omega$ and inductance $5\, H$ is connected to a $100\, V$ battery. The energy stored in the coil will be .... $J$.