The permeability of a metal is $0.1256 \ TmA^{-1}$. Its relative permeability will be (Given: $\frac{\mu_0}{4 \pi} = 10^{-7} \ SI \ unit$,$\pi = 3.14$).

$A$ solenoid has a core of a material with relative permeability $400$. The windings of the solenoid are insulated from the core and carry a current of $2 \; A$. If the number of turns is $1000$ per metre,calculate $(a) \; H$,$(b) \; M$,$(c) \; B$ and $(d)$ the magnetising current $I_m$.

Explain the magnetic susceptibility $(\chi)$ of a material. From it,explain the relative magnetic permeability and magnetic permeability of the material. Obtain the relation between them.

The relation between total magnetic field $(B)$,magnetic intensity $(H)$,permeability of free space $(\mu_{0})$,and magnetic susceptibility $(\chi)$ is:

The relation between $\mu$ and $H$ for a specimen of iron is $\mu = [\frac{0.4}{H} + 12 \times 10^{-4}] \ H m^{-1}$. The value of $H$ which produces a flux density of $1 \ T$ will be ($\mu =$ magnetic permeability,$H =$ magnetic intensity).

The susceptibility of $Al$ is $2 \times 10^{-5}$. The percent increase in the magnetic field when the space within a current-carrying toroid is filled with $Al$ is: