A permanent magnet
Attracts all substances
Attracts only magnetic substances
Attracts magnetic substances and repels all non-magnetic substances
Attracts non-magnetic substances and repels magnetic substances
The dipole moment of a short bar magnet is $1.25\, A-m^2$. The magnetic field on its axis at a distance of $0.5$ metre from the centre of the magnet is
The magnetism of magnet is due to
A magnetic needle of negligible breadth and thickness compared to its length, oscillates in a horizontal plane with a period $T$. The period of oscillation of each part obtained on breaking the magnet into $n$ equal parts perpendicular to the length is
Write the difference between electric field lines and magnetic field lines.
The magnetic potential due to a magnetic dipole at a point on its axis situated at a distance of $20 \mathrm{~cm}$ from its center is $1.5 \times 10^{-5} \ \mathrm{Tm}$. The magnetic moment of the dipole is___________ $\mathrm{Am}^2$. (Given : $\frac{\mu_0}{4 \pi}=10^{-7} \ \mathrm{TmA}^{-1}$ )