What instrument is commonly used to measure atmospheric pressure?
A. Thermometer
B. Barometer
C. Hygrometer
D. Anemometer
Correct Answer: B (Barometer)
Explanation:
Atmospheric pressure is the force per unit area exerted by the weight of the atmosphere. It is commonly measured with an instrument called a barometer, which measures the height of a column of mercury or other fluid in response to changes in atmospheric pressure. The two most common types of barometers are mercury barometers and aneroid barometers. Mercury barometers use a column of mercury in a glass tube to measure atmospheric pressure, while aneroid barometers use a flexible metal capsule that expands or contracts in response to changes in pressure.