Question

Mention the factors on which resistance of a conductor depends and hence define resistivity.

Answer 1

Resistance $\left(R\right)\propto Resistivity\left(\rho \right)$

Resistance $\left(R\right)\propto Length\left(l\right)$ of resistance wire

Resistance $\left(R\right)\propto \frac{1}{A}$, where A is area of cross-section of wire

$\Rightarrow R=\frac{\rho l}{A}$

Resistivity a measure of the resisting power of a specified material to the flow of an electric current.It is inverse of conductivity

$\Rightarrow Resistivity\left(\rho \right)=\frac{1}{Conductivity\left(\sigma \right)}$