Question

a superconductor is capable of repelling a magnet so that it hovers just above the surface of the superconductor. which statement explains why the magnet can hover above the superconductor?
the direction of the net force is up.
the gravitational force acting on the magnet is zero.
the direction of the magnetic force and the gravitational force are the same.
the magnitude of the magnetic force acting on the magnet and weight of the magnet are equal.

Explanation:

1. Analyze each option:

• Option 1: The net force being up would mean the magnet accelerates upward, not hovers. So this is incorrect.
• Option 2: Gravitational force (weight) on the magnet is \( F_g = mg \), which is not zero as long as the magnet has mass and is in a gravitational field. So this is incorrect.
• Option 3: Magnetic force repels (upward) and gravitational force is downward, so their directions are opposite, not the same. Incorrect.
• Option 4: For the magnet to hover (be in equilibrium), the upward magnetic force must balance the downward gravitational force (weight). So their magnitudes are equal, and directions are opposite, resulting in a net force of zero. This is correct.

Answer:

The magnitude of the magnetic force acting on the magnet and weight of the magnet are equal.