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

If the velocity of a galaxy relative to the Earth is $1.2 \times 10^6 \, m/s$,then the percentage increase in the wavelength of light from the galaxy as compared to a similar source on Earth will be ...............$\%$

If a star emitting yellow light is accelerated towards the Earth,then to an observer on Earth,it will appear:

In the hydrogen spectrum,the wavelength of the ${H_\alpha}$ line is $656 \ nm$,whereas in the spectrum of a distant galaxy,the ${H_\alpha}$ line wavelength is $706 \ nm$. The estimated speed of the galaxy with respect to the Earth is:

$A$ galaxy is moving away from the Earth at a speed of $286 \, km/s$. The shift in the wavelength of a red line at $630 \, nm$ is $x \times 10^{-10} \, m$. The value of $x$,to the nearest integer,is........
[Take the value of speed of light $c$ as $3 \times 10^{8} \, m/s$]

The velocity of light emitted by a source $S$ observed by an observer $O$,who is at rest with respect to $S$,is $c$. If the observer moves towards $S$ with velocity $v$,the velocity of light as observed will be