Optics Question 427
Question: A telescope of diameter 2m uses light of wavelength 5000 Å for viewing stars. The minimum angular separation between two stars whose image is just resolved by this telescope is
[MP PET 2003]
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:
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 $
