A star is moving towards the earth with a speed of `9 xx 10^(6) m//s`. If the wavelength of a particular spectral line emitted by star is `600 nm`, find the apparent wavelength.

A star is moving towards the earth with a speed of 4 xx 10^(7) m//s . If the wavelength emitted by the star is 500 nm , what would be the change in wavelength received on earth ?

A star is moving away from the earth with a velocity of 10^(5) m/sec. If wavelength of its spectral line be 5700 Å , the Doppler's shift will be

Earth is moving towards a stationary star with a velocity 100 kms^(-1) . If the wavelength of light emitted by the star is 5000Å, then the apparent change in wavelength observed by the observer on earth will be

A star is receding from earth with a velocity 3 xx 10^(6) m//s . If the actual wavelength of the light emitted by the star is lambda and Delta lambda is the displacement in wavelength as observed on earth then Delta lambda : lambda is -