Chapter-10|Wave Optics|NCERT 12th Physics:
Doppler’s Effect in Light:
The change in frequency or wavelength of the light wave due to the relative motion between the light source and the observer is called Doppler’s Effect.
Negative(-) sign indicates source is moving away from observer.
When light source moving away from the observer, the frequency received by the observer will be less than the frequency transmitted by the source. This cause a shift towards the red end of the visible light spectrum. Astronomers call it as the redshift.
When the light source move towards the observer, the frequency received by the observer will be more than the frequency transmitted by the source. This cause a shift towards the blue end of the visible spectrum. Astronomers call it as the blueshift.
