The self-induced $e.m.f.$ in a $0.1 \, H$ coil when the current in it is changing at the rate of $200 \, A/s$ is......$V$

$A$ choke coil works on the principle of

The length of a solenoid is $\ell$,whose windings are made of a material of density $D$ and resistivity $\rho$. The winding resistance is $R$. The inductance of the solenoid is (where $m$ = mass of winding wire,$\mu_{0}$ = permeability of free space).

The dimensional formula of self-inductance is . . . . . . .

In a coil of self-inductance $0.5 \, H$,the current varies at a constant rate from $0 \, A$ to $10 \, A$ in $2 \, s$. The $e.m.f.$ generated in the coil is ... $V$.

$A$ coil of wire of radius $r$ has $600$ turns and self-inductance of $108 \ mH$. The self-inductance of a coil with the same radius and $500$ turns is (in $mH$)