In a circular conducting coil,when current increases from $2 \,A$ to $18 \,A$ in $0.05 \,s$,the induced $e.m.f.$ is $20 \,V$. The self-inductance of the coil is.....$mH$.

The ratio of the number of turns per unit length of two solenoids $A$ and $B$ is $1: 3$ and the lengths of $A$ and $B$ are in the ratio $1: 2$. If the two solenoids have the same cross-sectional area,the ratio of the self-inductances of the solenoids $A$ and $B$ is

If the number of turns per unit length in a solenoid is tripled,the self-inductance of the solenoid will

$A$ magnetic flux of $5 \mu Wb$ is linked with a coil when a current of $1 \ mA$ flows through it. Calculate the self inductance of the coil.

The inductance of a solenoid $0.5 \, m$ long of cross-sectional area $20 \, cm^2$ and with $500$ turns is......$mH$

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