Doppler Effect and its applications

• Doppler’s effect can be defined as an observed change in frequency of a wave (for eg., Sound wave) when an observer and source have relative motion between them.
• The Doppler Effect has several real-world applications. Some of them are given below.
• Police radar “gun” to check the speed of oncoming vehicles.
• In meteorology, to track storms.
• In the medical field such as to draw echocardiograms and in medical ultra-sonography to diagnose heart and vascular problems.
• It is used to measure the speed at which stars and galaxies are approaching or receding from us, in a mechanism named red shift or blue shift.

Source: NCERT