Q. On increasing the length by $0.5\ mm$ in a steel wire of length $2\ m$ and area of cross-section $2\ mm^{2}$, the force required is [$Y$ for steel $= 2.2 \times 10^{11}N/m^{2}$]

A) $1.1 \times 10^{5}N$
B) $1.1 \times 10^{4}N$
C) $1.1 \times 10^{3}N$
D) $1.1 \times 10^{2}N$
Explanation

(d) $F = \frac{YAl}{L} = \frac{2.2 \times 10^{11} \times 2 \times 10^{- 6} \times 5 \times 10^{- 4}}{2} = 1.1 \times 10^{2}N$

Dr. Abubacker
Reviewed by Dr. Abubacker

Physics Educator & NEET/JEE Specialist

Ph.D. in Physics with 19+ years of teaching experience.