• # question_answer Consider the following statements. 1. Absolute humidity is an amount of water vapour, usually discussed per unit volume. 2. Specific humidity is the ratio of the partial pressure of water vapour in the air-water mixture to the saturate vapour pressure of water at those conditions. 3. Relative humidity is the ratio of water vapour to dry air in a particular mass and is sometimes, referred to as humidity ratio. 4. A device used to measure relative humidity is called a psychrometer. Which of the statements given above are correct? A)  2 and 3            B)  1, 2 and 3          C)  1 and 4            D)  All of these

[c] Absolute humidity is an amount of water vapour, usually discussed per unit volume. Absolute humidity in air ranges from zero to roughly 30 grams per cubic meter, when the air is saturated at$30{}^\circ \,\,C$. The absolute humidity changes as air temperature or pressure changes. Relative humidity is the ratio of the partial pressure of water vapour in the air-water mixture to the saturated vapour pressure of water at those conditions. The relative humidity of air depends not only on temperature, but also on pressure of the system of interest. Relative humidity is an important metric used in weather forecasts and reports, as it is an indicator of the likelihood of precipitation, dew or tog. In hot summer weather, a rise in relative humidity increases the apparent temperature to humans (and other animals) by hindering the perspiration from the skin. Specific humidity is the ratio of water vapour to dry air in a particular mass and is sometimes referred to as humidity ratio. There are various devices used to measure and regulate humidity, A device used to measure relative humidity is called a psychromeier hygrometer.