Question

Due to Doppler?? effect the shift in wavelength observed is 0.1 ? for a star producing wavelength 6000 ?. Velocity of recession of the star will be

• A. 5 km/s
• B. 25 km/s
• C. 20 km/s
• D. 10 km/s

Answer 1

Answer: (A)

5 km/s

Answer 2

The formula for Doppler shift $\frac{\Delta\lambda}{\lambda}=\frac{v}{c}$ $v=\frac{\Delta \lambda}{\lambda}. c=\frac{0.1}{6000}\times3\times10^{8}=0.5\times10^{4}=5 \, km \, s^{-1}$