1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

# A beam of light AO is incident on a glass slab (μ=1.732) in the direction shown. The reflected ray OB is passed through a Nicol prism. On viewing through a Nicol prism, we can find on rotating the prism that

A
the intensity is reduced down to zero and remains zero.
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
the intensity reduces down somewhat and rises again.
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
there is no change in intensity.
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
the intensity gradually reduces to zero and then again increases.
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
Open in App
Solution

## The correct option is D the intensity gradually reduces to zero and then again increases. According to Brewster's law μ=tanip ⇒ip=tan−1(1.732)=tan−1(√3)=60∘ From the figure, i=60∘ As, i=iP ∴ Brewster's law is satisfied, so the reflected ray OB will be plane polarized. We know when a plane polarized light is passed through a Nicol prism (polaroid), the intensity of emergent light varies as I=I0cos2θ ∴ On rotating Nicol prism, θ varies, When θ=90∘, I=0 and when θ=0∘, I=I0. So, the intensity of the emergent ray gradually reduces to zero and then again increases. So option (D) is correct. Why this Question? Concept : Condition of application of Brewster's law and variation of intensity of plane polarized light with angle between the transmission axis of polarizer and analyser.

Suggest Corrections
7
Join BYJU'S Learning Program
Related Videos
Total Internal Reflection
PHYSICS
Watch in App
Explore more
Join BYJU'S Learning Program