Question

a wire of length 'L' and area of cros section 'A has the resistance'R' if the wire is stretched to thrice its lenght for the new resistance​

Answer 1

Answer:

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