Advertisements
Advertisements
Question
Show, via a suitable diagram, how unpolarised light can be polarised by reflection.
Solution
An ordinary beam of light on reflection from a transparent medium becomes partially polarised. The degree of polarisation increases as the angle of incidence is increased. At a particular value of angle of incidence, the reflected beam becomes completely polarised. This angle of incidence is called the polarising angle (p).
When light is incident at polarising angle at the interface of a refracting medium, the refractive index of the medium is equal to the tangent of the polarising angle.
μ = tan p
where
μ → Refractive index of the refracting medium
p → Polarising angle
APPEARS IN
RELATED QUESTIONS
Two polaroids P1 and P2 are placed with their pass axes perpendicular to each other. An unpolarised light of intensity Io is incident on P1. A third polaroid P3 is kept in between P1 and P2 such that its pass axis makes an angle of 45° with that of P1. Determine the intensity of light transmitted through P1, P2 and P3
Using the phenomenon of polarisation, show how the transverse nature of light can be demonstrated.
The refractive indices of glass and water w.r.t. air are 3/2 and 4/3 respectively. Determine the refractive index of glass w.r.t. water.
What is the Brewster angle for air to glass transition? (Refractive index of glass = 1.5)
When a low flying aircraft passes overhead, we sometimes notice a slight shaking of the picture on our TV screen. Suggest a possible explanation.
Greenlight is an incident at the polarising angle on a certain transparent medium. The angle of refraction is 30°.
Find
(i) polarising angle, and
(ii) refractive index of the medium.
Light transmitted by Nicol prism is ______.
What is plane polarised light?
State and obtain Malus’ law.
List the uses of polaroids.
