Optics Question 102
Question: An astronaut is looking down on earth’s surface from a space shuttle at an altitude of $ 400km. $ Assuming that the astronaut’s pupil diameter is $ 5mm $ and the wavelength of visible light is $ 500nm. $ The astronaut will be able to resolve linear object of the size of about
[AIIMS 2003]
Options:
A) 0.5 m
B) $ 5m $
C) 50 m
D) 500 m
Show Answer
Answer:
Correct Answer: C
Solution:
$ \frac{x}{r}=\frac{1.22\ \lambda }{d}\Rightarrow x=\frac{1.22\ \lambda r}{d} $
$ =\frac{1.22\times 500\times {{10}^{-9}}\times 400\times 10^{3}}{5\times {{10}^{-3}}}=50\ m $
