Explain factors that change the resistivity of conducting materials.
Temperature- Electrical resistance of most metals rises with increase of temperature whereas those of semiconductors and electrolytes reduce with increase of temperature.
Alloying- It is another factor, that affects the resistivity of a material. With the addition of several impurities to a metal, its resistivity can be changed. It has higher resistivity than that of pure metal.
Mechanical stressing-If a material undergoes a mechanical treatment, its resistivity changes because of mechanical distortion of the crystal structure. For example annealing decreases the resistivity.
Age Hardening- it increases the resistivity of an alloy.