Question 4: Discuss super conductivity of a conductor with the help of a curve.

## Definition of superconductor

Superconductor is a material that can conduct electricity or transport electrons from one point to another with no resistance.

Explanation: When current flows through a conductor, the lattice atoms offer a resistance to the flow of electrons. Almost whole of the resistance is due to the continuous vibration of the lattice atoms. When the temperature is decreased, the amplitude of vibration also decreases; this decreases the resistance of the material. A point reaches when the resistance is practically zero. At this point the conductor is said to be superconductor.

### Critical temperature

Temperature at which at which a material becomes superconductor is called critical temperature, denoted by Tc.

## Explanation by a curve

The process is depicted for mercury in the curve above.

Temperature of Mercury decreases from some point, say A, towards B. At B, the resistance of the conductor (mercury) becomes zero and it starts behaving like a super conductor.