Question

The length of wire is being doubled.calculate it's new resistance.

Answer 1

Answer:

But resistance is also inversely proportional to the area of cross-section, and as area of cross-section is halved due to doubling of length, the resistance is once more doubled due to the halfing of the area of cross-section. So overall the resistance of the wire becomes four times the original resistance.

Answer 2

Answer:

R = p L/A

V = A× L

A = V/L

R = p L^2/V

R ~ L^2

Length Doubled

Resistance 4 times