An air core solenoid has $1000$ turns and is one metre long. Its cross-sectional area is $10 \, cm^2$. Its self-inductance is: (in $, mH$)

The self-inductance of a solenoid is:

When the current changes from $+2 \, A$ to $-2 \, A$ in $0.05 \, s$,an $e.m.f.$ of $8 \, V$ is induced in a coil. The coefficient of self-induction of the coil is ... $H$.

$A$ graph of magnetic flux $(\phi)$ versus current $(I)$ is shown for four inductors $P, Q, R, S$. The largest value of self-inductance is for inductor:

An emf of $2.8 \ mV$ is induced in a rectangular loop of area $150 \ cm^2$ when the current in the loop changes from $3 \ A$ to $8 \ A$ in a time of $0.2 \ s$. Then the self-inductance of the loop is (in $\mu H$)

$A$ toroid is a long coil of wire ($N$ turns) wound over a circular core. The coefficient of self-induction of the toroid is [The magnetic field in it is uniform and $R >> r$,where $r=$ radius of wire,$R=$ radius of coil] ($\mu_0=$ permeability of free space).