Which term is listed as a humidity expression along with dew point and humidity ratio?

• A. Latent heat
• B. Dew point
• C. Humidity ratio
• D. Relative humidity

Answer: (A)

Humidity expressions describe how much moisture is present in the air. Dew point indicates the temperature at which air becomes saturated and moisture begins to condense. Humidity ratio (or mixing ratio) is the mass of water vapor per mass of dry air. Relative humidity then tells you how close the air is to that saturation point, expressed as a percentage. Latent heat, by contrast, is the energy involved in changing the phase of water (for example, evaporating or condensing), not a measure of moisture content. So the term that fits as a humidity expression alongside dew point and humidity ratio is relative humidity.