A steel tape is calibrated at $20^{\circ} C$. On a cold day when the temperature is $-15^{\circ} C$, percentage error in the tape will be ……….. $\%$ $\left[\alpha_{\text {steel }}=1.2 \times 10^{-5}{ }^{\circ} C ^{-1}\right]$

Thermal expansion of a solid is due to the

A beaker is filled with water at $4\,^oC$. At one time the temperature is increased by few degrees above $4\,^oC$ and at another time it is decreased by a few degrees below $4\,^oC$. One shall observe that:

If a bimetallic strip is heated, it will

The coefficient of apparent expansion of mercury in a glass vessel is $132 ×\times10^{-6}/^oC$ and in a steel vessel is $114 \times 10^{-6}/^oC$ . If $\alpha $ for steel is $12 \times 10^{-6}/^oC$ , then that of glass is