The current in a coil changes from $4 \, A$ to $0 \, A$ in $0.1 \, s$. If the average induced $e.m.f.$ is $100 \, V$,what is the self-inductance of the coil in $H$?

The current passing through a coil of $120$ turns and inductance $40 \text{ mH}$ is $30 \text{ mA}$. The magnetic flux linked with the coil is:

The length of a wire required to make a solenoid of length $l$ and self-induction $L$ is

$A$ long solenoid has $500$ turns. When a current of $2 \,A$ is passed through it, the resulting magnetic flux linked with each turn of the solenoid is $4 \times 10^{-3} \,Wb$. The self-inductance of the solenoid is: (in $\,H$)

$A$ circuit has self-inductance $L$ and carries a current $I$. To prevent sparking when the circuit is switched off,a capacitor which can withstand potential difference $V$ is used. The least capacitance is

Current in a circuit falls from $5.0 \, A$ to $0.0 \, A$ in $0.1 \, s$. If an average $emf$ of $200 \, V$ is induced,give an estimate of the self-inductance of the circuit in $H$.