Question

if length of a wire is doubled without stretching how will it effect th resistance ​

Answer 1

since resistance is directly proportional to length of conductor, and as you have mentioned that the wire is not stretched, physics says that resistance will get doubled.

hope it helps

Answer 2

Answer:

Resistance is directly proportional to the length of the wire, and inversely proportional to the cross sectional area of the wire. ... Doubling the length will double the resistance, but the wire also must get thinner as it is stretched, because it will contain the same amount of metal in twice the length.