Question

When a copper sphere is heated, maximum percentage change will be observed in:

• A. Radius
• B. Area
• C. Volume
• D. None of these

Answer 1

The correct option is C Volume

Change in radius $=\frac{\Delta r}{r}=X$

Change in area $=\frac{\Delta \left(4\pi r^2\right)}{(4\pi r^2})=\frac{\Delta r^2}{r^2}=\frac{2\Delta r}{r}=2X$

Change in Volume $=\frac{\Delta \left(4/3\pi r^3\right)}{(4/3\pi r^3})=\frac{\Delta r^3}{r^3}=\frac{3\Delta r}{r}=3X$

Thus change in volume is maximum.