What is are Resistivity Laws?

What is are  Resistivity  Laws?

Resistivity Definition

Resistivity is defined as a material’s property that opposes the flow of electrical current.

Factors Affecting Resistance

Resistance depends on length, cross-sectional area, material nature, and temperature.

Unit of Resistivity

The unit of resistivity is Ω-m in the MKS system and Ω-cm in the CGS system.

First Law of Resistivity

Resistance increases with the length of the substance.

Second Law of Resistivity

Resistance decreases with a larger cross-sectional area.

Resistivity

That means resistance of a material of unit length having unit cross – sectional area is equal to its resistivity or specific resistance. Resistivity of a material can alternatively be defined as the electrical resistance between opposite faces of a cube of unit volume of that material.

Third Law of Resistivity

The resistance of a substance is directly proportional to the resistivity of the materials by which the substance is made.

Fourth Law of Resistivity

Temperature affects the resistance of a substance.