question_answer

In hydrogen spectrum the wavelength of \[{{H}_{\alpha }}\] line is 656 nm, whereas in the spectrum of a distant galaxy, \[{{H}_{\alpha }}\] line wavelength is 706 nm. Estimated speed of the galaxy with respect to earth is,

A)  \[2\times {{10}^{8}}m/s\]

B)  \[2\times {{10}^{7}}m/s\]

C)  \[2\times {{10}^{6}}m/s\] 

D)  \[2\times {{10}^{5}}m/s\]