Question

The temperature of a wire of length $1$ meter and area of cross-section $c{m}^2$ is increased from $0^{\circ }C$ to ${100}^{\circ }C$ rod is not allowed to increase in length$,$ the force required will be $(\alpha ={10}^{-5}{/}^{\circ }C$ and $Y={10}^{11}N/M^2)$

• A. ${10}^{3}N$
• B. ${10}^{4}N$
• C. ${10}^{5}N$
• D. ${10}^{9}N$

Answer 1

Answer: (C)

${10}^{5}N$

The Force in the wire is given by

$F=\text{force developed}=YA\alpha \left(\Delta \theta \right)={10}^{11}\times {10}^{-4}\times {10}^{-5}\times 100={10}^{4}N$