Q. The resistance of a wire is $R.$ If the length of the wire is doubled by stretching, then the new resistance will be
A) $2R$
B) $4R$
C) $R$
D) $\frac{R}{4}$
Explanation
(b) $R \propto l^{2} \Rightarrow$ If $l$ doubled then $R$ becomes 4 times
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.