Question

There is some change in the length when a 33000 N tensile force is applied on a steel rod of area of cross section ${10}^{-3}{m}^2$. The change in temperature required to produce the same elongation if the steel rod is heated is (The modulus of elasticity is $3\times {10}^{11}N{m}^{-2}$ and coefficient of linear expansion of steel is $1.1\times {10}^{-5}{}^{-1}$ )

• A. 20
• B. 15
• C. 10
• D. 0

Answer 1

Answer: (C)

10

Elongation due to tensile force $\left(F\right)=\frac{33000}{{10}^{-3}\times 3\times {10}^{11}}=1.1\times {10}^{-4}$

Coefficient of linear expansion $\left(\alpha \right)$ is $1.1\times {10}^{-5}$

Change of temperature $dT$ required to produce the same elongation is given by: $\alpha dT=1.1\times {10}^{-4}$

Hence, $dT={10}^{o}C$