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प्रश्न
How is polarisation of light obtained by scattering of light?
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उत्तर
- The light from a clear blue portion of the sky shows a rise and fall of intensity when viewed through a polaroid that is rotated.
- This is because of sunlight, which has changed its I direction (having been scattered) on encountering the molecules of the earth’s atmosphere.
- The electric field of light interacts with the electrons present in the air molecules.
- Under the influence of the electric field of the incident wave the electrons in the molecules acquire components of motion in both these directions.
- We have an observer looking at 90° to the direction of the sun. Clearly, charges accelerating parallel do not radiate energy towards this observer since their acceleration has no transverse component.
- The radiation scattered by the molecule is therefore polarized perpendicular to the plane.
Polarisation by scattering
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संबंधित प्रश्न
Draw a neat labelled diagram showing the plane of vibration and plane of polarisation for polarised light.
Three identical polaroid sheets P1, P2 and P3 are oriented so that the pass axis of P2 and P3 are inclined at angles of 60° and 90° respectively with the pass axis of P1. A monochromatic source S of unpolarised light of intensity I0 is kept in front of the polaroid sheet P1 as shown in the figure. Determine the intensities of light as observed by the observer at O, when polaroid P3 is rotated with respect to P2 at angles θ = 30° and 60°.
Find an expression for intensity of transmitted light when a polaroid sheet is rotated between two crossed polaroids. In which position of the polaroid sheet will the transmitted intensity be maximum?
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
What is the Brewster angle for air to glass transition? (Refractive index of glass = 1.5)
A ray of light passes from a vacuum to a medium of refractive index (μ). The angle of
incidence is found to be twice the angle of refraction. The angle of incidence is _______.
A) `cos^(-1)(mu/2)`
B) cos−1(μ)
C) `2 cos^(-1) (mu/2)`
D) `2 sin^(-1) (mu/2)`
With the help of an experiment, state how will you identify whether a given beam of light is polarised or unpolarized?
What does a polaroid consist of? How does it produce a linearly polarised light?
A beam of light is incident at the polarizing angle of 35° on a certain glass plate. The refractive index of the glass plate is :
A ray of light is incident on a transparent medium at a polarizing angle. What is the angle between the reflected ray and the refracted ray?
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.
Discuss polarisation by selective absorption.
What is a polariser?
What is plane polarised light?
State Brewster’s law.
Discuss about pile of plates.
Discuss about Nicol prism.
An unpolarised light of intensity 32 Wm-2 passes through three Polaroids such that the axes of the first and the last Polaroids are at 90°. What is the angle between the axes of the first and middle Polaroids so that the emerging light has an intensity of only 3 Wm-2?
For the same objective, find the ratio of the least separation between two points to be distinguished by a microscope for light of 5000 Å and electrons accelerated through 100 V used as the illuminating substance.
A polarizer - analyser set is adjusted such that the intensity of light coming out of the analyser is just 10% of the original intensity. Assuming that the polarizer - analyser set does not absorb any light, the angle by which the analyser need to be rotated further to reduce the output intensity to be zero, is ______.
