Current in a circuit falls from $5.0 \ A$ to $0.0 \ A$ in $0.1 \ s$. If an average emf of $100 \ V$ is induced,then the value of self-inductance of the circuit is . . . . . . . (in $H$)

The self-inductance of a coil is $L$. Keeping the length and area the same,the number of turns in the coil is increased to four times. The self-inductance of the coil will now be

If a current of $10 \, A$ flows in one second through a coil,and the induced $e.m.f.$ is $10 \, V$,then the self-inductance of the coil is:

$A$ current of $0.5 \ A$ is passed through the winding of a long solenoid having $400$ turns. The magnetic flux linked with each turn is $3 \times 10^{-3} \ Wb$. The self-inductance of the solenoid is: (in $H$)

Two solenoids of equal number of turns have their lengths as well as radii in the same ratio $1: 3$. The ratio of their self-inductance will be

Select the incorrect unit of self inductance.