Optics Question 454
Question: A telescope of diameter 2 m uses light of wavelength 5000 A for viewing stars. The minimum angular separation between two stars whose image is just resolved by this telescope is
Options:
A) $ 4\times {{10}^{-4}} $ rad
B) $ 0.25\times {{10}^{-6}} $ rad
C) $ 0.31\times {{10}^{-6}} $ rad
D) $ 5.0\times {{10}^{-3}} $ rad
Show Answer
Answer:
Correct Answer: C
Solution:
[c] Minimum angular separation $ \Delta \theta =\frac{1}{R.P}=\frac{1.22\lambda }{d} $
$ =\frac{1.22\times 5000\times {{10}^{-10}}}{2}=0.3\times {{10}^{-6}}rad $
