Table 2.

Corresponding equations in SI and cgs Gaussian (or cgs emu). In this table, F refers to force, W refers to the energy of a magnetic dipole in a filed, w refers to the volume energy density. Other symbols are defined in table 1.

Gaussian (or cgs emu)	SI
B = H + 4πM	B = μ0 (H + M) (1)
	B = μ0 H + J (2)
χ= M/H	κ= M/H (3)
$\text{F}=\chi \text{VH}\frac{\partial \text{H}}{\partial x}$	F = μ0 κVH ∂H/∂x (4)
W = −mBcosθ	W = − mBcosθ (5)
$\text{w}=\frac{\text{BH}}{8\pi }$	$\text{w}=\frac{1}{2}\text{BH}$ (6)