Which instrument is used to measure atmospheric pressure? A) Thermometer B) Barometer C) Hygrometer D) Anemometer
VerifiedAnswer: B) Barometer
Explanation:
A barometer is the correct instrument used to measure atmospheric pressure. This device plays a crucial role in weather forecasting and understanding atmospheric conditions around us.
The barometer was invented by Italian physicist Evangelista Torricelli in 1643. It works on the principle that atmospheric pressure changes with weather conditions and altitude. When air pressure increases, it indicates fair weather, while decreasing pressure often signals approaching storms or bad weather.
There are two main types of barometers:
• Mercury Barometer: Uses a column of mercury in a glass tube. The height of the mercury column changes with atmospheric pressure variations. • Aneroid Barometer: Contains a sealed metal chamber that expands and contracts with pressure changes, moving a needle on a dial.
Now let's understand why the other options are incorrect. A thermometer measures temperature, not pressure. It contains substances like mercury or alcohol that expand and contract with temperature changes. A hygrometer measures humidity or moisture content in the air, helping us understand how much water vapor is present in the atmosphere. An anemometer measures wind speed and sometimes wind direction, making it essential for weather monitoring and aviation.
Atmospheric pressure is typically measured in units like millibars (mb), inches of mercury (inHg), or pascals (Pa). Standard atmospheric pressure at sea level is approximately 1013.25 millibars or 29.92 inches of mercury. This pressure decreases as we go higher in altitude, which is why mountain climbers often experience difficulty breathing at high elevations.
