Question

Magnetic permeability is maximum for :

• A. paramagnetic substances
• B. ferromagnetic substances
• C. diamagnetic substances
• D. all of the above

Answer 1

Answer: (B)

Magnetic permeability is a measure of its conduction of magnetic lines of force through it.
Magnetic permeability $(\mu )$ is defined as the ratio of the magnetic induction $\vec{B}$ inside the magnetised substance to the magnetic intensity $H$ of the magnetising field
$\mu =\frac{\vec{B}}{\vec{H}}$
Ferromagnetic substances are strongly magnetised in relatively weak magnetising field in the same direction as the field.
They have relative permeabilities of the order of hundreds and thousands. While paramagnetic substances are freely attracted by a magnet and diamagnetic substances are feebly repelled by a magnet.
Hence, magnetic permeability is maximum for ferromagnetic substances.