Magnetism and Matter

Assertion : Paramagnetic substances get
poorly attracted in magnetic field.
Reason : Because magnetic dipoles are
aligned along external magnetic field weakly.

\(\alpha\)-particle is revolving in a circular path with radius \(r\) with speed \(v\), then find the value of magnetic dipole moment.

The horizontal component of the earth's magnetic field at any place is \(0.36 \times 10^{-4} \mathrm{~Wb} / \mathrm{m}^2\). If the angle of dip at that place is \(60^{\circ}\), then the value of vertical component of the earth's magnetic fi...

Assertion : The magnetism of magnet is due to the spin motion of electrons.
Reason : Dipole moment of electron is smaller than that due to orbit motion around nucleus.

The angle of dip, if dip needle oscillating in vertical plane makes 40 oscillations per min in a magnetic meridian and 30 oscillations per minute in vertical plane at right angle to the magnetic meridian is