Define doppler effect and its application

The Doppler effect 

  • It is a change in frequency or wavelength of a wave in relation to an observer who is moving relative to the source of the wave. 
  • It is named after Austrian physicist Christian Doppler.

DROPPLER EFFECT


  • A common example of the Doppler effect is the change in pitch of a siren on a moving ambulance. 
  • As the ambulance approaches, the sound waves are compressed, causing the pitch to increase. 
  • As the ambulance moves away, the sound waves are stretched, causing the pitch to decrease.


In physics, the Doppler effect is used in a variety of applications, such as:

  • Sonar and radar: to measure the speed of objects, such as ships or aircraft.
  • Astronomy: to measure the velocity of stars and galaxies.
  • Medical imaging: to study blood flow in the human body, using ultrasound.
  • Weather forecasting: to track storms, by measuring the Doppler shift of the radar signals they reflect.