Steel is preferred to soft iron for making permanent magnets because,

If $$\theta_1$$ and $$\theta_2$$ be the apparent angles of dip observed in two vertical planes at right angles to each other, then the true angle of $$\operatorname{dip} \theta$$ is given by

The magnetic permeability '$$\mu$$' a of a paramagnetic substance is :

Find the pole strength of a magnet of length $$2 \mathrm{~cm}$$, if the magnetic field strength $B$ at distance $$10 \mathrm{~cm}$$ from the centre of a magnet on the axial line of the magnet is $$10^{-4} \mathrm{~T}$$.