Question

Why the needle of galvanometer gets oppositely deflected when the bar magnet is taken inside and outside the non current carrying solenoid in Faraday experiment?

Answer 1

When the magnet is held stationary, the galvanometer shows no deflection.
When the north pole of the magnet is brought towards the coil, the galvanometer shows a sudden deflection indicating that a current is induced in the coil.
The galvanometer deflection is temporary and it lasts as long as the bar magnet is in motion. There won't be any deflection when the bar magnet is held stationary anywhere.
When the magnet is moved away from the coil, the galvanometer shows deflection in the opposite direction indicating the direction of induced current in the reversed direction.
deflection in the galvanometer will be larger when the magnet is pushed or pulled away from the coil faster.
This indicates that when there is a relative motion between the coil and the magnet a current gets induced in the coil. This current gets detected with the help of galvanometer.
This experiment shows that a current flows in the coil only when there is a relative motion between the coil and the magnet due to which the galvanometer connected with the coil shows deflection.The direction of deflection in a galvanometer is reversed if the direction of motion (or polarity of the magnet) is reversed
direction of deflection is reversed because the direction of induced current is reversed when bar magnet is taken inside and outside.