Question

What do you mean by specific resistance? Give its SI unit.

Answer 1

1. The resistance offered by the material per unit length and per unit cross-section area of the conductor is known as the specific resistance or resistivity of the material.
2. Specific resistance is a property of a material and depends only on the nature of the material.
3. It is denoted by $\rho$ and is given by the equation $\rho =\frac{RA}{L}$ where R is the resistance of a conductor, A is the area of cross-section and L is the length of the conductor.
4. Substituting all the units in the above equation, we get the SI unit of specific resistance as ohm-metre ($\Omega m$).