A short solenoid of radius $a$, number of turns per unit length $n_{1}$ and length $L$ is kept coaxially inside a very long solenoid of radius $b$, number of turns per unit length $n_{2}$. What is the mutual inductance of the system?
Electromagnetic Induction is a current produced by the voltage production due to a changing magnetic field. This happens in one of the two conditions:-
When we place the conductor in a changing magnetic field.
When the conductor constantly moves in a stationary field.