Question

How does the paired electrons in the diamagnetic substances cancel the magnetic moments?

Answer 1

because both electron have opposite spin hence they cancel each other's magnetic moments in diamagnetic substance

Answer 2

$\underline \bold{Diamagnetic\: Substance}$

Diamagnetic substance are the substance those when are placed in the external magnetic field becomes feebly magnetize in the direction opposite to the field.

In other words, we can see date diamagnetic substance are the substance which when placed in the external magnetic field becomes feebly repulsive .

Diamagnetic substance are the temperature independent substance and the magnetism is due to the pair of electrons revolving in opposite sense.

In this material, the electrons revolve in pair and in opposite sense such that the net magnetic moment is zero.

But when they are held in the magnetic field, then Lorentz force supports the centripetal force of one electron and oppose to the other electron and hence the magnetic moment of one electron increases and of other one decreases. And their become in and magnetic moment opposite to the applied field.