Optics Question 893
Question: Two polaroids have their polarizing directions parallel so that the intensity of a transmitted light is maximum. The angle through which either polaroid must be turned if the intensity is to drop by one-half is
Options:
A) $ 135{}^\circ $
B) $ 90{}^\circ $
C) $ 120{}^\circ $
D) $ 180{}^\circ $
Show Answer
Answer:
Correct Answer: A
Solution:
[a] For $ I=\frac{I _{0}}{2} $ and $ I=I _{0}{{\cos }^{2}}\theta =\frac{I _{0}}{2} $
$ \therefore \theta =45^{o} $
Therefore the angle through which either polaroids turned is $ 135{}^\circ (=180{}^\circ -45{}^\circ ) $
