Humidity of air is measured by ___________.

Correct option is A

The correct answer is (a) Hygrometer

A hygrometer is an instrument used to measure the humidity (the amount of moisture or water vapor) in the air.

How it Works:
Measures the relative humidity by comparing the moisture content in the air to the maximum amount the air can hold at a given temperature.

Uses:

• Meteorology
• Weather forecasting
• Controlling humidity in industries, homes, and greenhouses.

Additional Information:

• Nanometer: A unit of length in the metric system, equal to one-billionth of a meter; used to measure very small distances like wavelengths of light.
• Glucometer: A device used to measure blood sugar levels in people with diabetes.
• Barometer: An instrument used to measure atmospheric pressure, important for weather prediction.