With what speed should a galaxy move outward with respect to earth so that the sodium-D line at wavelength 5890 Å is observed at 5896 Å ?
- (A)
- (B)
- (C)✓ Correct
- (D)
Answer: (C)
Solution
Using the Doppler shift formula for light: , where Å and Å. Therefore, m/s km/s.
JEE Main · 2021 · 20 Jul 2021 · Shift 2 · Single correct option