Question

The length of a brass rod is found to be less on a hot summer day than on a cold winter day as measured by the same aluminium scale. Can we conclude that brass shrinks on heating?

Answer 1

Conclusion on brass shrinks on heating

• Due to the heat during the hot summer days, metals tend to expand. The coefficients of expansion are different for different metals.

• Aluminium has a coefficient of linear expansion which is more than that of brass.

• Therefore, as measured by the aluminium scale, aluminium will expand more than brass, and this leads to the length of the brass rod to decrease apparently.

• Hence, it cannot be concluded that upon heating brass shrinks or aluminium expands more than brass.