Question

A bar magnet of magnetic moment 3.0 Am is placed in a uniform magnetic field of 2 × 10^-5T. If each pole of the magnet experience a force of 6 × 10^-4 N, the length of the magnet is ______.

Options

• 0.5 m

• 0.3 m

• 0.2 m

• 0.1 m

Answer 1

A bar magnet of magnetic moment 3.0 Am is placed in a uniform magnetic field of 2 × 10^-5T. If each pole of the magnet experience a force of 6 × 10^-4 N, the length of the magnet is 0.1 m.

Explanation:

τ = MB

F × L = MB

F = `"M"/"L" xx "B"`

`6 xx 10-4 = 3/"L" xx 2 xx 10^-5`

L = 0.1 m