If a hole is made at the centre of a bar magnet, then its magnetic moment will
Increase
Decrease
Not change
None of these
Calculate the axial field of a finite solenoid.
Verify the Gauss’s law for magnetic field of a point dipole of dipole moment ${{\rm{\vec m}}}$ at the origin for the surface which is a sphere of radius $\mathrm{R}$.
Points $A$ and $B$ are situated perpendicular to the axis of a $2\,cm$ long bar magnet at large distances $X$ and $3X$ from its centre on opposite sides. The ratio of the magnetic fields at $ A$ and $B$ will be approximately equal to
A small magnetised needle $P$ placed at point $O$ and the arrow shows the direction of its magnetic moment. The other arrow show different position (and orientation) of another identical magnets $(Q)$. In which configuration system is not in equilibrium
The small magnets each of magnetic moment $10 \,A-m^2$ are placed end-on position $0.1\,m$ apart from their centres. The force acting between them is....$N$