The weather report reads, “Temperature 20°C: Relative humidity 100%”. What is the dew point?

Dew point is 20.

Explanation

Formula for relative humidity is given as

Where both actual vapor pressure and saturation vapor pressure are at same temperature.

Given

Temperature of air =20

Relative humidity=100%

So,

actual vapor pressure =saturation vapor pressure at the temperature 20

The temperature at which relative humidity is 100% i.e. air is completely saturated, is called dew point.

Here, the temperature at which the air is completely saturated is 20.

So, dew point is 20.