Question

Two identical copper rods, one hollow and the other solid are heated to the same rise in temperature. Will the two rods expand equally or unequally?

Answer 1

1. When a metal rod is heated, its length increases this is called the linear expansion in the metallic rod.
2. The rise in length of the metal rod depends upon the original length of the metal rod, the rise in temperature and the nature of the material of the rod.
3. The thermal expansion in the metal rod also depends upon the amount of heat energy present in the metallic rod with rising temperature.
4. Two metallic rods one of which is hollow and the other a solid are heated for the same rise in temperature.
5. Then, it is observed that the hollow metallic rod expands less than the solid rod.
6. It is due to the reason that in the solid rod more heat is present for the same rise in temperature.
7. This happens as a solid rod has a very large no. of molecules in compare to the hollow rod that traps more heat.

Thus, we can conclude that in the case of two identical copper rods, one hollow and the other solid, the solid copper rod will expand more than the hollow one that is unequal.