(N/A) The different ways to induce an electric current in a coil are based on the principle of electromagnetic induction:
$(a)$ Moving a coil rapidly between the two poles of a horse-shoe magnet: When the magnetic flux linked with the coil changes due to its motion in a magnetic field,an induced current is generated in the coil.
$(b)$ Moving a magnet relative to a stationary coil: When a magnet is moved towards or away from a coil,the magnetic field lines passing through the coil change,which induces an electric current in the coil.
$(c)$ Changing the current in a nearby coil: If a second coil carrying a varying current is placed near the first coil,the changing magnetic field produced by the second coil induces a current in the first coil (mutual induction).