The effective length of a magnet is $ 31.4 \,cm $ and its pole strength is $0.5\, Am$. The magnetic moment, if it is bent in the form of a semicircle will be.....$A{m^2}$

A bar magnet of magnetic moment $M$ is placed at right angles to a magnetic induction $B.$ If a force $F$ is experienced by each pole of the magnet, the length of the magnet will be

Two bar magnets having same geometry with magnetic moments $M$ and $2 M$, are firstly placed in such a way that their similar poles are same side then its time period of oscillation is $T_{1}$. Now the polarity of one of the magnet is reversed then time period of oscillation is $T_{2},$ then

A short bar magnet with its north pole facing north forms a neutral point at $P$ in the horizontal plane. If the magnet is rotated by $90^o$ in the horizontal plane, the net magnetic induction at $P$ is (Horizontal component of earth’s magnetic field = ${B_H}$)

A bar magnet is cut into two equal parts then which of the following quantity may change

$(a)$ Intensity of magnetization

$(b)$ Pole strength

$(c)$ Magnetic moment

Assume the dipole model for earth’s magnetic field $\mathrm{B}$ which is given by

${{\rm{B}}_{\rm{v}}} = $ vertical component of magnetic field

$ = \frac{{{\mu _0}}}{{4\pi }}\frac{{2m\,\cos \theta }}{{{r^3}}}$

${{\rm{B}}_H} = $ Horizontal component of magnetic field

${{\rm{B}}_H} = \frac{{{\mu _0}}}{{4\pi }}\frac{{m\,\sin \theta }}{{{r^3}}}$

$\theta $ $= 90^{°}$ -latitude as measured from magnetic equator.

$(a)$ Find loci of points for which : $\left| {{\rm{\vec B}}} \right|$ is minimum;