Question

The temperature at which the air becomes saturated with water vapour is called as-
A.Evaporation temperature
B.Dew point temperature
C.Sublimation temperature
D.Vaporization temperature

Answer 1

Hint:Water vapor is always present in the atmosphere in varying quantities. When air rises from earth, it starts cooling down. The lower the air temperature becomes the possibility of formation of water vapor increases and at a particular temperature the air becomes saturated with water vapor.

Complete step-by-step answer:Evaporation temperature is a temperature at which water is converted into its gaseous state at room temperature.
Water vapor is nothing but water in its gaseous state. Evaporation is a surface phenomenon in which the molecules of water on the surface start vaporizing. It is a constant process.
So when water from earth’s surface rises upwards in the form of water vapor where air becomes cool and the humidity increases.
At a particular temperature the air becomes saturated with water vapor which is called dew point.
This critical temperature is called dew point temperature.
When the air is cooled below the dew point, the excess water vapor will start condensing and the water vapor will change to its original state i.e. liquid state.
Sublimation temperature is the temperature at which a particular solid is directly converted to its gaseous phase.
When a liquid changes to vapor phase, the process is called vaporization and the temperature at which the process occurs is known as vaporization temperature.

The correct answer is option ‘B’.

Note:Dew point temperature depends on absolute humidity. Absolute humidity is measured in gram per cubic meter. In humid air the dew point is higher when compared to the dry air. Generally air that is cooled to its dew point condenses to form clouds.