Lenz's Law

The north pole of the magnet points upward toward the coil. Magnetic field lines leave a north pole, so the field passes upward through the coil.

As the magnet moves closer to the coil, more field lines pass through it. Therefore, the upward flux is increasing.

By Lenz's Law, the induced current must oppose the increase in upward flux. Therefore, the induced current must create a magnetic field pointing downward through the coil.

To produce a downward field through the coil, point your right thumb downward and curl your fingers. When viewed from above, the fingers curl in the clockwise direction.

The induced current flows clockwise when viewed from above. This makes the bottom face of the coil act as a north pole, repelling the approaching north pole of the magnet.

We need to find the direction of the induced current when a north pole approaches the bottom of a coil from below.

The option 'No current is induced' is wrong because the magnet is moving, which means the magnetic flux through the coil is changing. A changing flux always induces a current.

'The current alternates direction rapidly' is incorrect. Alternating current is produced by a continuously rotating magnet (like in a generator). A magnet simply approaching in one direction produces a steady induced current in one direction.

'Anti-clockwise' (viewed from above) would produce an upward field through the coil — which would reinforce the increasing upward flux. This would violate Lenz's Law and conservation of energy.

'Clockwise' (viewed from above) produces a downward field inside the coil, opposing the increasing upward flux. This correctly applies Lenz's Law.

Electromagnetic induction requires a change in magnetic flux through a conductor. The flux must be increasing, decreasing, or fluctuating for a current to be induced.

The magnet is held perfectly still inside the coil. Because there is no relative motion and the magnet's strength is not changing, the magnetic flux through the coil is constant.

Since the flux is not changing ($\Delta \Phi =0$), no EMF is induced and therefore no current flows in the coil, regardless of how strong the magnet is.

The correct answer is that no current is induced because the flux is not changing. The strength of the field alone does not matter — only a change in flux can induce a current.

This question tests whether students understand that motion or change is essential for induction — not just the presence of a magnetic field.

This is a common misconception. Field strength does not cause induction on its own — the field must be changing. A stronger stationary magnet still induces zero current.

Being inside the coil is irrelevant if nothing is moving. Position alone cannot induce a current; only a change in flux can.

Current direction only matters when a current actually flows. Since no current is induced in a stationary scenario, this option is irrelevant and incorrect.

'No current is induced because the flux is not changing' is correct. This directly reflects the fundamental requirement for electromagnetic induction.