Explain what is meant by neutral points? How will you calculate magnetic moment of a bar magnet by locating the neutral points?

Options

A. two
B. four
C. eight
D. infinite

Answer

D

Explanation

Direction of magnetic field intensity at a point on the bisector of the magnet is opposite to the magnetic moment of magnet. Magnetic moment of bar magnet is parallel to Earth.s magnetic field and hence direction of magnetic field intensity due to bar magnet will be opposite to Earth.s magnetic field. For point at some fixed distance from the centre of magnet, magnetic field intensity becomes equal to that of Earth and at these points net field becomes zero. We can draw a circle of appropriate radius around the magnet in the plane in which the perpendicular bisector of the magnet lies. We shall get infinite number of points on this circle.