The Doppler effect is applicable for

If light from a galaxy observed on the earth's surface has a red shift,then:

$A$ star emitting radiation at a wavelength of $5000 \; \mathring{A}$ is approaching Earth with a velocity of $1.5 \times 10^6 \; m/s$. The change in wavelength of the radiation as received on Earth is ....... $\mathring{A}$.

The apparent wavelength of light from a star moving away from the earth is $0.02 \%$ more than the actual wavelength. The velocity of the star is $[c = 3 \times 10^8 \ m/s]$. (in $km/s$)

If a star is moving towards the Earth,then the spectral lines are shifted towards:

For a specific wavelength $670 \; nm$ of light coming from a galaxy moving with velocity $v$,the observed wavelength is $670.7 \; nm$. The value of $v$ is ............