# Magnetising Force

The degree to which a magnetic field can magnetise a material is expressed in terms of magnetizing force.

Consider a toroidal solenoid with n turns per unit length carrying a current I. The magnetic induction of the field produced will be

B = μnI

The product nI is called magnetizing force, that is

H = nI

Therefore

B = μH

Therefore, magnetizing force may be defined as the number of ampere turns flowing round unit length of toroidal solenoid to produce magnetic induction B in the solenoid.