Question

For ferromagnetic material, the relative permeability $\left({\mu }_r\right)$ versus magnetic intensity $(H)$ has which of the following shape?

• A.
• B.
• C.
• D.

Answer 1

Answer: (C)

${\mu }_r=1+\frac{I}{H};$ as we know $I$ is dependent on $H$, initially
value of $\frac{I}{H}$ is smaller so value of ${\mu }_r$ increases with
$H$ but slowly but with further increases of $H$ value of $\frac{I}{H}$ also increases i.e., ${\mu }_r$ increases rapidly. When
material is fully magnetised $I$ becomes constant, then with the increase of $H(\frac{I}{H}$ decreases) ${\mu }_r$ decreases.