Due to Doppler's effect, the shift in wavelength observed is `0.1 Å` for a star producing wavelength 6000 Å. Velocity of recession of the star will be

Options

A. `20 kms^(-1)`
B. `2.5 kms^(-1)`
C. `10 kms^(-1)`
D. `5 kms^(-1)`

Answer

D

Explanation

Shifting in wavelength `Delta lambda = 0.1 Å`
`lambda = 6000 Å`
`V/C = (Delta lambda)/(lambda)`
`V = (Delta lambda C)/(lambda)`
`= (0.1 xx 10^(-10) xx 3 xx 10^4)/(6000 xx 10^(-10))`
`= 0.5 xx 10^4 ms^(-1) = 5 kms^(-1)`