The self-induced $emf$ of a coil is $25\,V$. When the current in it is changed at a uniform rate from $10\,A$ to $25\,A$ in $1\,s$,the change in the energy stored in the inductor is......$J$.

In the part of an a.c. circuit as shown,the resistance $R=0.2 \ \Omega$. At a certain instant,$(V_{A}-V_{B})=0.5 \ V$,$I=0.5 \ A$ and $\frac{dI}{dt}=8 \ A/s$. The inductance of the coil is (in $H$)

The $SI$ unit of inductance,the henry,cannot be written as:

$A$ copper wire is wound on a wooden frame,whose shape is that of an equilateral triangle. If the linear dimension of each side of the frame is increased by a factor of $3$,keeping the number of turns of the coil per unit length of the frame the same,then the self-inductance of the coil:

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

The adjoining figure shows two bulbs $B_1$ and $B_2$,a resistor $R$,and an inductor $L$. When the switch $S$ is turned off,what happens to the bulbs?