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

Assertion : Paramagnetic substances get poorly attracted in magnetic field.

Reason : Because magnetic dipoles are aligned along external magnetic field weakly.

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 field will be (in $$\mathrm{Wb} / \mathrm{m}^2$$ )