Question

A 4ohm resistance wire is doubled on it. Calculate the new resistance of wire?​

Answer 1

Answer:

We consider wire is doubled on it means to fold the length of wire. It means its length will get half and area of cross section will get doubled. Thus, R' = p' l'/A' = p (l /2) ÷ 2A = !/4 (p l / A) = 1/4R = 1/4 × 4 = 1Ω.