Explain superconductivity and explain the effect of magnetic field on superconductors.

Various metals become superconducting below a temperature that is the characteristic of the particular metal. All have zero resistivity and the temperature at that this change takes place is termed as superconducting transition temperature. All metals, whose are good conductors at room temperature as gold, tin and silver do not exhibit superconducting properties. While metals and compounds that have superconducting properties at exact temperatures are insulators at room temperature.

This is possible to destroy superconductivity with the application of a strong magnetic field. While, the magnetic field exceeds an exact critical value, the superconducting state disappears, magnetic field penetrates material and electrical resistance is restored.