Relative humidity is related to what?

Correct answer: Present water vapour and maximum capacity of air

Correct answer: A. Relative humidity compares the actual amount of water vapour in the air with the maximum amount that air can hold at the same temperature. It is usually expressed as a percentage: relative humidity = actual water vapour ÷ saturation capacity × 100. If air contains half of its possible moisture, its relative humidity is about 50 percent. Temperature matters because warm air generally has a greater moisture-holding capacity. B is incorrect because sea depth is a physical measurement and does not define atmospheric humidity. C is unrelated to the amount of moisture in air. D is incorrect because mountain height alone cannot define relative humidity, although height and cooling can influence local conditions. A is correct because it gives both parts of the comparison. Memory cue: relative humidity means ‘how full the air is with moisture’ compared with its capacity.