JEE Main Physics Class 12 Electromagnetic Induction Questions

Case (a): When bar magnet is entering with constant speed, flux ( ϕ ) will change and an e.m.f. is induced, so galvanometer will deflect in positive direction.
Case (b): When magnet is completely inside, flux ( ϕ ) will not change, so galvanometer will show null deflection.
Case (c) : When bar magnet is making on exit, again flux(\ϕ) will change and an e.m.f. is induced in opposite direction so galvanometer will deflect in negative direction i.e. reverse direction.