Question

If length of a wire is hafte and its area of cross section is doubled then what will be the resistance of the wire

Answer 1

The resistance would become 1/4th.

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

Where R is the resistance, rho the resistivity (constant), A the CSA and l the length of the wire.

If A is doubled, and l halved, we get:

$R' = \rho \frac{\frac{l}{2}}{2A} = \rho \frac{l}{4A} = \frac{R}{4}$

Answer 2

Explanation:

If length of a wire is hafte and its area of cross section is doubled then