CBSE Class 12 · 2011 · Magnetic Properties of MatterVery Short Answer

An iron needle is kept near a strong bar magnet. It will experience:

Assertion (A): Diamagnetic substances exhibit magnetism.
Reason (R): Diamagnetic materials do not have a permanent magnetic dipole moment.

The magnetic field and angle of dip at a place on the earth are $0.3\text{G}$ and $30^{\circ }$, respectively. The value of the vertical component of the earth's magnetic field at the place is ____.

(a) State Gauss's law for magnetism. Explain its significance.
(b) Write the four important properties of the magnetic field lines due to a bar magnet.

Write three points of difference between para-, dia- and ferro-magnetic materials, giving one example for each.

A bar magnet of magnetic moment $6{\text{J T}}^{-1}$ is aligned at $60^{\circ }$ with a uniform external magnetic field of $0.44\text{T}$. Calculate (a) the work done in turning the magnet to align its magnetic moment (i) normal to the magnetic field, (ii) opposite to the magnet …