Coefficient of linear expansion of brass and steel rods are $\alpha_1$ and $\alpha_2$. Lengths of br

Question

Coefficient of linear expansion of brass and steel rods are $\alpha_1$ and $\alpha_2$. Lengths of brass and steel rods are $l_1$ and $l_2$ respectively. If ( $l_2-l_1$ ) is maintained same at all temperatures, which one of the following relations holds good?

Professor PC Thomas Classes · Answer

For difference to be constant, $\Delta l_1 = \Delta l_2 \implies l_1 \alpha_1 \Delta T = l_2 \alpha_2 \Delta T \implies l_1 \alpha_1 = l_2 \alpha_2$.