Ahectopascal
BBarometer
Ctorr
Dthermometer
Answer:
A. hectopascal
Read Explanation:
Atmospheric pressure
Like every matter, air also has weight. The weight exerted by the air in the atmosphere is the atmospheric pressure. Barometer is the instrument used for measuring atmospheric pressure which is recorded in the units hectopascal (hpa) or millibar (mb).
As a result of insolation, the atmospheric air expands, becomes less dense and rises up. This air movement is called air current. Consequently, the pressure decreases. Air moves from high pressure regions to low pressure regions. Such air movement is called wind.
Electricity can be generated from winds. Wind energy is being generated in places like Ramakkalmedu in Idukki district and Kanjikkode in Palakkad district.
Anemometer is the instrument used for measuring the wind speed. Wind vane is used to find the direction of wind.