Question

Factors affecting resistivity

Answer 1

There are many factors which affect the resistivity of a conductor.
1) The temperature of the conductor is directly proprtional to the resistivity of the conductor.
2) The resistivity also depends on the material of which the conductor is made up of.

Answer 2

Resistivity

The resistivity of a material is the resistance of a wire of that material of unit length and unit cross-sectional area. 

The unit for resistivity is the ohm-metre. 

The resistivity of a material depends on its nature and the temperature of the conductor, but not on its shape and size. 

A good conductor has less resistivity, whereas a bad conductor or insulator has high resistivity. The resistivity of semi-conductors lies between that of conductors and insulators. 

The resistivity of a metallic conductor increases with an increase in its temperature, whereas the resistivity of a semi-conductor decreases with an increase in its temperature.

The resistance of some materials decreases tremendously with a decrease in temperature in the very low temperature range of the order of absolute zero. Such substances are called superconductors. 

Conductivity is the reciprocal of resistivity, and determines the ability of a material to conduct electric current.