Q. The force required to stretch a steel wire of 1 $cm^{2}$ cross-section to 1.1 times its length would be $\left( Y = 2\ \times 10^{11}Nm^{- 2} \right)$
A) $2\ \times 10^{6}\ N$
B) 2 $\times 10^{3}\ N$
C) 2 $\times 10^{5}\ N$
D) 2 $\times 10^{- 6}\ N$
Explanation
(a) $F = \ \ YA\frac{\mathrm{\Delta}L}{L} = 2\ \times 10^{11} \times \left( 10^{- 4} \right) \times 0.1 = 2 \times 10^{6}\ N$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.