$A$ bar magnet has length $3 \,cm$, cross-sectional area $2 \,cm^2$ and magnetic moment $3 \,Am^2$. The intensity of magnetization of the bar magnet is

$A$ bar magnet has length $4 \text{ cm}$,cross-sectional area $2 \text{ cm}^2$ and magnetic moment $6 \text{ Am}^2$. The intensity of magnetisation of the bar magnet is

When a piece of a magnetic substance is placed in a uniform magnetic field,the flux density inside it is four times the flux density away from the piece. The magnetic permeability of the material is

The magnetic susceptibility of a material is $7.54 \times 10^{-3}$. The nature and relative permeability of the substance are:

An iron rod of volume $10^{-4} \, m^3$ and relative permeability $1000$ is placed inside a long solenoid wound with $5 \, \text{turns/cm}$. If a current of $0.5 \, A$ is passed through the solenoid, then the magnetic moment of the rod is .... $A m^2$.

Write the equation of the magnetic field obtained in the core of a solenoid in the form of $\vec{H}$ and $\vec{M}$.