1Which of these has the same dimensions as magnetisation?
Magnetisation and magnetising field both have the dimensions [L⁻¹ A].
MagnetismClass 12, Magnetism and Matter
Dimensional formula of Magnetisation
[L-1 A]
Magnetic moment per unit volume.
How to get the dimensional formula of magnetisation
- Start from the definition: magnetisation = magnetic moment / volume.
- area = length × length, so area is [L] × [L] = [L2].
- magnetic moment = electric current × area, so magnetic moment is [A] × [L2] = [L2 A].
- volume = length3, so volume is [L]3 = [L3].
- Put in the dimension of each part: [L2 A] / [L3].
- Add the powers of each base quantity: [L-1 A].
Quantities with the dimensions [L⁻¹ A]
Equal dimensions do not make them the same quantity. Compare magnetisation with the others in the full grid.
Three questions on magnetisation
2What is the SI unit of magnetisation?
The SI unit of magnetisation is the ampere per metre (A/m).
3Do magnetisation and magnetic field have the same dimensions?
Magnetisation is [L⁻¹ A] but magnetic field is [M T⁻² A⁻¹].
Magnetisation: quick answers
What is the dimensional formula of magnetisation?
The dimensional formula of magnetisation is [L⁻¹ A]. It comes from magnetisation = magnetic moment / volume.
What is the SI unit of magnetisation?
The SI unit of magnetisation is the ampere per metre (A/m).
Which quantities have the same dimensions as magnetisation?
Magnetisation shares [L⁻¹ A] with magnetising field. Equal dimensions do not make them the same quantity.