If in a coil the rate of change of area is $5 \, m^2/ms$ and the current changes from $2 \, A$ to $1 \, A$ in $2 \times 10^{-3} \, s$. If the magnetic field is $1 \, T$,then the self-inductance of the coil is......$H$

$A$ long solenoid of $N$ turns has a self-inductance $L$ and area of cross-section $A$. When a current $i$ flows through the solenoid,the magnetic field inside it has magnitude $B$. The current $i$ is equal to:

Current in a circuit falls from $5.0 \ A$ to $0.0 \ A$ in $0.1 \ s$. If an average emf of $100 \ V$ is induced,then the value of self-inductance of the circuit is . . . . . . . (in $H$)

If in a coil,the rate of change of area is $5 \, m^2/ms$ and the current changes from $2 \, A$ to $1 \, A$ in $2 \times 10^{-3} \, s$. If the magnitude of the magnetic field is $1 \, T$,then the self-inductance of the coil is ... $H$.

$A$ 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:

When a current in the conducting coil is changed from $5 \ A$ in one direction to $5 \ A$ in the opposite direction in $0.5 \ s$,an average induced e.m.f. in the coil is $2 \ V$. The self-inductance of the coil is (in $mH$)