An electric string of length l is elastically stretched through a length e by a force F. The area of cross-section of the string is A and its Young’s modulus is E. Which of the following expressions is correct?

A. F = EA/eI
B. F = EAI/e
C. F = EAe/l
D. F = EAe

Correct Answer:

Option C = F = EAe/l

Explanation
E = Stress/Strain = F/A/e/L
E = FL/AE; F = EAe/L