Two identical short bar magnets, each having magnetic moment $M,$ are placed a distance of $2d $ apart with axes perpendicular to each other in a horizontal plane. The magnetic induction at a point midway between them is
$\frac{{{\mu _0}}}{{4\pi }}(\sqrt 2 )\frac{M}{{{d^3}}}$
$\frac{{{\mu _0}}}{{4\pi }}(\sqrt 3 )\frac{M}{{{d^3}}}$
$\left( {\frac{{2{\mu _0}}}{\pi }} \right)\,\frac{M}{{{d^3}}}$
$\frac{{{\mu _0}}}{{4\pi }}(\sqrt 5 )\frac{M}{{{d^3}}}$
The magnetic field lines due to a bar magnet are correctly shown in
Two identical thin bar magnets each of length $l $ and pole strength $m$ are placed at right angle to each other with north pole of one touching south pole of the other. Magnetic moment of the system is
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.....$m$
The earth’s magnetic field at the equator is approximately $0.4 \;G$. Estimate the earth’s dipole moment.
The name magnet came from which island ?