# What is magnetising field | magnetism and matter class 12

## What is magnetising field?

When a magnetic material is placed in a magnetic field, a magnetism is induced in it. Thus the magnetising field can be defined as:

Magnetising field: The magnetic field that exists in vaccum and induces magnetism in any magnetic material is called magnetising field. [latexpage]

## Magnetising field explanation

Lets consider a toroidal solenoid that carrying a current $I$ and that’s placed in vaccum. If the solenoid has $n$ turns per unit length, then the magnetic field setup in the solenoid is given by: $$B_0=\mu_0 nI$$ So the magnetic field that arise in the toroidal solenoid due to the free current called magnetising field.