[" 168.In hydrogen spectrum,the wavelength of "H_(alpha)" line is "656" nm,whereas in the spectrum "1],[" distant galaxy,"H_(alpha)" line wavelength is "706" nm.Estimated speed of the galaxy with respect "],[" earth is "],[[" (a) "2times10^(8)m/s," (b) "2times10^(7)m/s],[" (c) "2times10^(6)m/s," (d) "2times10^(7)m/s],[" 169.The periodic time of rotation of a certain star is "22" days and its radius is "7times10^(8)m" .If "]]