Question

If the temperature of a wire of length $2m$ area of cross-section $1{cm}^2$ is increased from $0^{\circ }C$ to ${80}^{\circ }C$ and is not allowed to increase in length, then force required for it is {$Y={10}^{10}N/m^2,\alpha ={10}^{-6}{/}^{o}C$}

• A. $80N$
• B. $160N$
• C. $400N$
• D. $120N$

Answer 1

The correct option is A $80N$

80N

Formula,

$F=YA\alpha \Delta T$

$={10}^{10}\times 0.0001\times {10}^{-6}\times (80-0)$

$\therefore F=80N$