Question

If r resistance of a wire length l is streched to double its length then what is the new resistance

Answer 1

Answer:

2R

Explanation:

R = K L/A

log R = log K L/A = log K + log L - log A

ΔR/R = ΔL/L -  ΔA/A = 1

new resistance = R + ΔR = 2R