In free space, the relation between magnetic flux density 'B' and magnetizing force 'H' is
1
B/H = μo, where μo = 4π × 10-7 Henry / m
2
B/H = μo, where μo = 4π × 107 Henry / m
3
H/B = μo, where μo = 4π × 10-7 Henry / cm
4
H/B = μo, where μo = 4π × 107 Henry / cm