Find out the $e.m.f.$ produced when the current changes from $0$ to $1 \, A$ in $10 \, s$,given $L = 10 \, \mu H$.

Current in a circuit falls from $5.0\, A$ to $0\, A$ in $0.1\, s$. If an average $emf$ of $200\, V$ is induced,estimate the self-inductance of the circuit in $H$.

$A$ coil is wound on a core of rectangular cross-section. If all the linear dimensions of the core are increased by a factor of $2$ and the number of turns per unit length of the coil remains the same, the self-inductance increases by a factor of (Assume, permeability is same).

When the number of turns in a coil is made $3$ times without any change in the length of the coil,its self-inductance becomes

The equivalent quantity of mass in electricity is . . . . . . .

Two coils have self-inductance $L_1$ and $L_2$. The current through them is increasing at a constant rate. If the power dissipated in both the coils is the same, then the ratio of energy stored in the coil having inductance $L_1$ to that in $L_2$ is