$A$ varying current in a coil changes from $10 \, A$ to $0 \, A$ in $0.5 \, s$. If the average $EMF$ induced in the coil is $220 \, V$,the self-inductance of the coil is ... $H$.

$A$ coil has $N$ turns and the current passing through it is $I$ ampere,resulting in a self-inductance of $L$ Henry. If the current changes to $5I$ $A$,the new self-inductance will be . . . . . . $H$.

$A$ circular coil of radius $R$ has $N$ turns of a wire. The coefficient of self-induction of the coil will be $(\mu_0 = \text{permeability of free space})$

The back $e.m.f.$ induced in a coil,when current changes from $1 \ A$ to $0 \ A$ in $1 \ ms$,is $4 \ V$. The self-inductance of the coil is:

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 $H$.

What length of a very thin wire is required to obtain a solenoid of length $l_0$ and inductance $L$?