Correct Answer - Option 2 : Diamagnetic substance
The correct answer is option 2) i.e. Diamagnetic substance
CONCEPT:
-
Diamagnetic substance: Diamagnetic substances are those substances that get weakly magnetized in the presence of an external magnetic field, in a direction opposite to that of the external magnetic field.
- Each atom of the material has an orbital and spin magnetic moment caused by the orbital motion and spin of electrons respectively.
- The vector sum of the spin and orbital moments gives the net magnetic field of the atom. In diamagnetic substances, the net magnetic moment of an atom is zero.
- Under the influence of an external magnetic field, each atom acquires an induced emf. This increases the speed of motion of electrons in one direction. As a result, each atom acquires a net magnetic moment in the opposite direction to that of the external field.
- Hence, they repel the external magnetic field.
EXPLANATION:
- The magnetic dipoles of each atom in a diamagnetic are always zero.
- A change in temperature can only affect the random thermal motion of the atom.
- Since each atom has zero magnetic dipole moment, the temperature cannot affect the net magnetic moment in any way.
Thus, diamagnetic substances are independent of temperature.
