In the context of the Doppler effect in light,the term 'red shift' signifies:

The periodic time of rotation of a certain star is $22$ days and its radius is $7 \times 10^8 \ m$. If the wavelength of light emitted by its surface is $4320 \ \mathring{A}$, the Doppler shift will be $(1 \ day = 86400 \ s)$

The $6563 \ \mathring{A}$ line emitted by a hydrogen atom in a star is found to be red-shifted by $5 \ \mathring{A}$. The speed with which the star is receding from the Earth is:

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 $km/s$)

What speed (in $km/s$) should a galaxy move with respect to us so that the sodium line at $589.0 \;nm$ is observed at $589.6 \;nm$?

Light coming from a star is observed to have a wavelength of $3737 \ \mathring{A}$,while its real wavelength is $3700 \ \mathring{A}$. The speed of the star relative to the earth is (Speed of light $c = 3 \times 10^8 \ m/s$).