Q. If the force constant of a wire is $K$, the work done in increasing the length of the wire by $l$ is
A) $K/2$
B) $Kl$
C) $Kl^{2}/2$
D) $Kl^{2}$
Explanation
(c) $K = \frac{F}{l}$ and $W = \frac{1}{2}Fl = \frac{1}{2}Kl \times l = \frac{1}{2}Kl^{2}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.