Question

If the bar magnet in exercise 5.13 is turned around by 180º, where will the new null points be located?

Answer 1

The magnetic field on the axis of the magnet at a distance d₁ = 14 cm, can be written as:

Where,

M = Magnetic moment

= Permeability of free space

H = Horizontal component of the magnetic field at d₁

If the bar magnet is turned through 180°, then the neutral point will lie on the equatorial line.

Hence, the magnetic field at a distance d₂, on the equatorial line of the magnet can be written as:

Equating equations (1) and (2), we get:

The new null points will be located 11.1 cm on the normal bisector.