$A$ closely wound coil of $100$ turns and of cross-section $1 \,cm^2$ has a coefficient of self-inductance $1 \,mH$. The magnetic induction at the centre of the core of the coil when a current of $2 \,A$ flows in it will be (in $Wb/m^2$):

$A$ coil of $N = 100$ turns carries a current $I = 5 \, A$ and creates a magnetic flux $\phi = 10^{-5} \, Wb$ per turn. The value of its inductance $L$ will be ...... $mH$.

An air core solenoid has $1000$ turns and is one metre long. Its cross-sectional area is $10 \, cm^2$. Its self-inductance is: (in $, mH$)

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:

Current in a coil changes from $4 \,A$ to zero in $0.1 \,s$ and the emf induced is $100 \,V$. The self inductance of the coil is (in $\,H$)

When the current in a coil changes from $8 \; A$ to $2 \; A$ in $3 \times 10^{-2} \; s$,the $e.m.f.$ induced in the coil is $2 \; V$. The self-inductance of the coil (in $mH$) is: