Which of the following instruments is used to measure pressure?

The correct answer is Barometer.

Key Points

• A barometer is an instrument used to measure atmospheric pressure.
• It is essential in weather forecasting and determining altitude.
• Barometers come in two main types: mercury barometers and aneroid barometers.
• Mercury barometers use mercury in a glass tube, while aneroid barometers use a small, flexible metal box called an aneroid cell.

Additional Information

• Atmospheric Pressure
  • It is the force exerted onto a surface by the weight of the air above that surface in the atmosphere of Earth (or that of another planet).
  • It is measured in units such as Pascals (Pa), millibars (mb), or inches of mercury (inHg).
• Mercury Barometer
  • Invented by Evangelista Torricelli in 1643.
  • Consists of a long glass tube filled with mercury, with one end open to the atmosphere.
• Aneroid Barometer
  • Does not use liquid; instead, it uses a small, flexible metal box (aneroid cell).
  • The cell expands or contracts with changes in atmospheric pressure, and this movement drives a mechanical pointer on a dial.
• Uses of Barometers
  • Weather forecasting by measuring atmospheric pressure changes to predict short-term changes in the weather.
  • Altitude determination, as atmospheric pressure decreases with an increase in altitude.