Question

How does the resistance of a wire vary with its cross-section area?

Answer 1

1. The obstruction to the flow of electrons in a conductor is called resistance.
2. The relation between the resistance ($R$), area of cross-section ($A$), resistivity ($\rho$) and length ($L$) of the wire is given below.
3. $R=\rho \frac{L}{A}$
4. From the above relation, it is clear that the resistance of a wire is inversely proportional to its area of cross-section.
5. More the area of the cross-section of the wire, the lesser the resistance of the wire and vice versa.

Hence, the resistance of a wire varies inversely with its cross-section area.