Magnetism and Matter

The magnetic susceptibility of a material of a rod is 499. The absolute permeability of vacuum is 4$\mathrm{\pi }$ x 10^-7 Hm^-1 .  The absolute permeability of the material of rod is

• $\mathrm{\pi } \times {10}^{-4} {\mathrm{Hm}}^{-1}$

• $2\mathrm{\pi } \times {10}^{-4} {\mathrm{Hm}}^{-1}$

• $3\mathrm{\pi } \times {10}^{-4} {\mathrm{Hm}}^{-1}$

• $4\mathrm{\pi } \times {10}^{-4} {\mathrm{Hm}}^{-1}$

At a certain place, the horizontal component of earth's magnetic field is $\sqrt{3}$ times the vertical component. The angle of dip at that place is

• 30°

• 60°

• 45°

• 90°

Magnetic field intensity H at the centre of a circular loop of radius r carrying current I emu is 

• $\frac{\mathrm{r}}{\mathrm{I}} \mathrm{oersted}$

• $\frac{2\mathrm{\pi I}}{\mathrm{r}} \mathrm{oersted}$

• $\frac{\mathrm{I}}{2\mathrm{\pi r}} \mathrm{oersted}$

• $\frac{2\mathrm{\pi r}}{\mathrm{I}} \mathrm{oersted}$

The intensity of magnetization of a bar magnet is 5.0 x 10⁴ Am^-1.The magnetic length and the area of cross section of the magnet are 12 cm and 1cm² respectively. The magnitude of magnetic moment of this bar magnet is (in SI unit)

• 0.6

• 1.3

• 1.24

• 2.4