Question

a wire is streched three times of its original size . find the resistance of wire. ​

Answer 1

Answer:

If The wire is stretched 3 times the original length, the cross-section of the wire is cut to 1/3rd it's the original cross-section. Since the resistance of a wire is given by R = rho*l/A the length while cutting the cross-section by 3x, the new resistance will be 9 times the original resistance.