Question

Define specific resistance and give its SI unit.

Answer 1

1. Resistance of a material is given by $R=\rho \frac{L}{A}$ , where $\rho$ is a constant called resistivity of the material,$L$is the length and$\mathrm{A}$ is the area of the conductor.
2. Therefore, $\rho =R\frac{A}{L}$
3. If both the area and its length are unity then,

$R=\rho$

4. The specific resistance, also known as the resistivity of a material is defined as the resistance of a wire offered per unit length and the unit cross-sectional area of the material when the known quantity of voltage is applied at its ends.

5. The unit of specific resistance is ohm-meter.