Question

Anemometer measures
1. Humidity of air
2. speed of air
3. depth of sea
4. Height above sea level
5. None of the above/More than one of the above

Answer 1

Correct Answer - Option 2 : speed of air

The correct answer is speed of air.

• Anemometer:It is an instrument used to measure the speed of the wind, which is a common weather station instrument, or to calculate any form of current gas.
  • The term is derived from the Greek word anemos meaning wind which was first explained by Leon Battista Alberti who was an Italian artist and an architect in the year 1450.
  • He used a mechanical anemometer which was placed perpendicular to the wind direction such that the wind velocity as indicated by the angle of inclination of the disc.
• Types of anemometer:
  • Cup anemometer: This consists of four hemispherical cups that are mounted on one end of the horizontal arms at equal angles on a vertical shaft. 
  • Hotwire anemometer: This consists of thin wire which is heated up to a certain temperature slightly more than atmospheric temperature. 
  • Windmill anemometer: This is a mechanical device similar to the regular windmill used to calculate the velocity of the wind. It consists of the axis of rotation running parallel to the direction of the wind. 
  • Laser Doppler anemometer: A beam of light is used which is further split into two beams. The velocity is determined by calculating the amount of light that has been reflected.
  • Sonic anemometer: Sound waves from this anemometer are used to obtain the speed of the wind. These waves are made to pass through the transducer. These find applications in aircraft and scientific wind turbines.

EXPLANATION:

• From the above discussion, it's clear that an anemometer is an instrument that measures wind speed and wind pressure.
•  Anemometers are important tools for meteorologists, who study weather patterns.
• They are also important to the work of physicists, who study the way air moves.

The correct option is 2.