When a current of $2 \ A$ is passed through a coil of $100$ turns,the magnetic flux associated with it is $5 \times 10^{-5} \ Wb$. Find the self-inductance of the coil.

In a fluorescent lamp choke (a small transformer),$100 \; V$ of reverse voltage is produced when the choke current changes uniformly from $0.25 \; A$ to $0 \; A$ in a duration of $0.025 \; ms$. The self-inductance of the choke (in $mH$) is estimated to be:

$A$ graph of magnetic flux $(\phi)$ versus current $(I)$ is plotted for four inductors $A, B, C, D$. Which inductor has the largest value of self-inductance?

What length of a very thin wire is required to obtain a solenoid of length $l_0$ and inductance $L$?

In a circular coil,when the number of turns is doubled and the resistance becomes $1/4$th of the initial value,then the inductance becomes ....... times.

Two coils have self-inductance $L_1 = 4 \, mH$ and $L_2 = 1 \, mH$ respectively. The currents in the two coils are increased at the same rate. At a certain instant of time,both coils are given the same power. If $I_1$ and $I_2$ are the currents in the two coils at that instant of time respectively,then the value of $\frac{I_1}{I_2}$ is: