Some equipotential surfaces of the magnetic scalar potential are shown in the figure. Magnetic field at a point in the region is
${10^{ - 4}}\,T$
$2 \times {10^{ - 4}}\,T$
$0.5 \times {10^{ - 4}}\,T$
None of these
Write the equation of dipole moment of magnet in the form of electric current.
A bar magnet of magnetic moment $3.0\, A-m^2$ is placed in a uniform magnetic induction field of $2 \times 10^{-5}\, T$. If each pole of the magnet experiences a force of $6 \times 10^{-4} \,N$, the length of the magnet is.....$m$
Force between two identical bar magnets whose centres are $r $ metre apart is $ 4.8\, N$ , when their axes are in the same line. If separation is increased to $2r,$ the force between them is reduced to.....$N$
The mid points of two small magnetic dipoles of length $d$ in end-on positions, are separated by a distance $x, (x > > d)$. The force between them is proportional to $x^{-n}$ where $n$ is
If a hole is made at the centre of a bar magnet, then its magnetic moment will