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 $(1 \ day = 86400 \ s)$

Light from the constellation Virgo is observed to increase in wavelength by $0.4\%$. With respect to Earth,the constellation is:

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

$A$ star is moving away from the Earth. An observer on the Earth will see the wavelength of light coming from the star as:

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 Doppler effect in sound,in addition to the relative velocity between the source and the observer,also depends on the individual motion of the source and the observer relative to the medium. However,the Doppler effect in light depends only on the relative velocity between the source and the observer. The reason for this is: