$A$ coil of insulated wire is connected to a galvanometer. Explain what happens if a bar magnet with its north pole towards one face of the coil is:
$(i)$ moved quickly towards the coil,
$(ii)$ kept stationary inside the coil,and
$(iii)$ moved quickly away from the coil?

(N/A) $(i)$ The increasing magnetic field induces an electric current in the coil,as a result of which the galvanometer shows a momentary deflection (e.g.,towards the right).
$(ii)$ Since there is no change in the magnetic field,no induced current is produced,and the galvanometer shows zero deflection.
$(iii)$ The magnetic field decreases,which induces an electric current in the coil,and the galvanometer shows a momentary deflection in the opposite direction (e.g.,towards the left).