The spectral line for a given element in the light received from a distant star is shifted towards longer wavelength side by `0.032%`. Deduce the velocity of star in the line of sight.

Options

A. `9.6xx10^(4)ms^(-1)`
B. `11.6xx10^(-4)ms^(-1)`
C. `12.6xx10^(-4)ms^(-1)`
D. None of these

Answer

A

Explanation

Here, `(Deltalamda)/lamda=(0.032)/(100)` (position, as the shift is towards longer wavelength)
Now, Doppler shift is given by,
`Deltalamda=-v/clamda`
`v=-(Deltalamda)/lamdac=-(0.032)/(100)xx3xx10^(8)=-9.6xx10^(4)ms^(-1)`
The negative sign indicates that the star is receding.