Optics Question 243
A star emits light of $ 5500\AA $ wavelength. It appears blue to an observer on the earth, it means
[DPMT 2002]
Options:
A) Star is going away from the earth
B) Star is not stationary
C) Star is approaching Earth
D) None of the above
Show Answer
Answer:
Correct Answer: C
Solution:
Blue radiations have the wavelength around 4600 $ \overset{o}{\mathop{A}} $ . It shows that apparent wavelength is smaller than the real wavelength. It means that the star is moving towards Earth.
BETA
