The correct option is (a).
Explanation
Humidity refers to the concentration of water vapour present in the air. The capacity of air to hold moisture and the rate of evaporation are governed by thermodynamic principles involving temperature and saturation levels.
Statement-wise Analysis:
- Statement 1 is Correct: Humidity is defined as the amount of water vapour or moisture present in the atmosphere at a specific time and place. It indicates the likelihood of precipitation, dew, or fog.
- Statement 2 is Incorrect: The capacity of air to hold water vapour is directly related to its temperature. As the temperature of the air increases, its capacity to hold moisture increases. Conversely, as air cools, its capacity to hold water vapour decreases, eventually leading to saturation and condensation.
- Statement 3 is Incorrect: The rate of evaporation is inversely proportional to the humidity of the surrounding air. On a humid day, the air already contains a high amount of water vapour, which reduces its ability to absorb more moisture from wet surfaces. Consequently, the rate of evaporation slows down, causing clothes to take longer to dry.
Key Takeaway:
Warmer air has a higher water-holding capacity than cooler air. High humidity reduces the rate of evaporation because the air is closer to its saturation point.