In the absence of an atmosphere,the average temperature on the surface of the Earth would be . . . . . . .

Maximum density of $H_2O$ is at the temperature

The temperature of a body is measured both in ${ }^{\circ} C$ and ${ }^{\circ} F$. $A$ graph is plotted with ${ }^{\circ} F$ on the $X$-axis and ${ }^{\circ} C$ on the $Y$-axis. Then,the cosine of the angle between the graph and the $X$-axis is

If the temperature of an object is $140^{\circ}F$,then its temperature in Celsius is ........ $^{\circ}C$.

Mercury is often used in clinical thermometers. Which one of the following properties of mercury is not a reason for this?

On the centigrade scale,the temperature of a body increases by $30$ degrees. The increase in temperature on the Fahrenheit scale is ..............