Question

One rod of copper and another identical rod of iron are heated to the same rise in temperature. Which rod will expand more? Give reason.

Answer 1

When two identical rods (same length) are of different material and heated to the same rise in temperature, the copper rod will expand more than iron, since expansion depends on the nature of the material.
(Coefficient of linear expansion of copper $17\times {10}^{-6}$ per °C > iron $13\times {10}^{-6}$ per °C)