Optics Question 247
Question: A star is moving away from the earth with a velocity of 100 km/s. If the velocity of light is $ 3\times 10^{8}m/s $ then the shift of its spectral line of wavelength $ 5700{AA} $ due to Doppler’s effect will be
[MP PMT 1994]
Options:
A) $ 0.63{AA} $
B) $ 1.90{AA} $
C) $ 3.80{AA} $
D) $ 5.70{AA} $
Show Answer
Answer:
Correct Answer: B
Solution:
$ \Delta \lambda =\lambda \frac{v}{c}=5700\times \frac{100\times 10^{3}}{3\times 10^{8}}=1.90{AA} $
