The current in self-inductance $L=40\; mH$ is to be increased uniformly from $1\; A$ to $11\; A$ in $4\; ms$. The $e.m.f.$ induced in the inductor during this process is ..... $V$.

When the number of turns in a coil is made $3$ times without any change in the length of the coil,its self-inductance becomes

$A$ $30\text{ cm}$ long solenoid has $10$ turns per cm and area of $5\text{ cm}^2$. The current through the solenoid coil varies from $2\text{ A}$ to $4\text{ A}$ in $3.14\text{ s}$. The e.m.f. induced in the coil is $\alpha \times 10^{-5}\text{ V}$. The value $\alpha$ is . . . . . . .

When current in a coil changes from $5\,A$ to $2\,A$ in $0.1\,s,$ an average voltage of $50\,V$ is produced. The self-inductance of the coil is.......$H$.

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 $H$)

In a coil,the current changes from $-2 \,A$ to $+2 \,A$ in $0.2 \,s$ and induces an emf of $0.1 \,V$. The self-inductance of the coil is: (in $\,mH$)