Q. A force of $200\ N$ is applied at one end of a wire of length $2m$ and having area of cross-section $10^{- 2}cm^{2}$. The other end of the wire is rigidly fixed. If coefficient of linear expansion of the wire $\alpha = 8 \times 10^{- 6}/℃$ and Young’s modulus $Y = 2.2 \times 10^{11}\ N/m^{2}$ and its temperature is increased by $5℃$, then the increase in the tension of the wire will be
A) $4.2\ N$
B) $4.4\ N$
C) $2.4\ N$
D) $8.8\ N$
Explanation
(d) Increase in tension of wire $= YA\alpha\mathrm{\Delta}\theta$
$= 8 \times 10^{- 6} \times 2.2 \times 10^{11} \times 10^{- 2} \times 10^{- 4} \times 5 = 8.8\ N$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.