Q. Two wires of copper having the length in the ratio 4:1 and their radii ratio as 1:4 are stretched by the same force. The ratio of longitudinal strain in the two will be
A) 1 : 16
B) 16 : 1
C) 1 : 64
D) 64 : 1
Explanation
(b) Strain $\propto$ Stress $\propto \frac{F}{A}$
Ratio of strain $= \frac{A_{2}}{A_{1}} = \left( \frac{r_{2}}{r_{1}} \right)^{2} = \left( \frac{4}{1} \right)^{2} = \frac{16}{1}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.