Optics Question 497
Question: The intensity of direct sunlight on a surface normal to the rays is $ I _{0} $ . What is the intensity of direct sunlight on a surface, whose normal makes an angle of 60o with the rays of the sun
[CPMT 1981]
Options:
A) $ I _{0} $
B) $ I _{0}( \frac{\sqrt{3}}{2} ) $
C) $ \frac{I _{0}}{2} $
D) $ 2I _{0} $
Show Answer
Answer:
Correct Answer: C
Solution:
$ {I _{\theta }}=I _{o}\cos \theta $
$ =I _{o}\cos 60^{o} $
$ =\frac{I _{o}}{2} $
