Question

When a copper ball is heated, the largest percentage increase will occur in its :

• A. Diameter
• B. Area
• C. Volume
• D. Density

Answer 1

Answer: (C)

Volume

The coefficient of volume expansion ($\gamma$) is twice as that of area expansion ($\beta$) and thrice as that of linear expansion ($\alpha$). Hence when a copper ball is heated the maximum percentage increase will be of the volume.
i.e., $\gamma =2\beta$ and $\gamma =3\alpha$
(a) Increase in diameter is linear expansion.
(b) Increase in surface area is area expansion.
(d) Density decreases with increase in temperature.