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प्रश्न
State two uses of Polaroid.
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उत्तर
Uses of Polaroid:-
(1) In motor car head lights – To remove headlight glare
(2) To improve color contrast in old oil paintings
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संबंधित प्रश्न
What is a Polaroid?
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°.

What dose a polaroid consist of?
How does one demonstrate, using a suitable diagram, that unpolarised light when passed through a Polaroid gets polarised?
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
Two polaroids P1 and P2 are placed with their pass axes perpendicular to each other. An unpolarised light of intensity I0 is incident on P1. A third polaroid P3 is kept in between P1 and P2 such that its pass axis makes an angle of 30° with that of P1. Determine the intensity of light transmitted through P1, P2 and P3
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)
Show using a proper diagram how unpolarised light can be linearly polarised by reflection from a transparent glass surface.
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?
What is the difference between polarised light and unpolarised light?
A ray of ordinary light is travelling in air. It is incident on air glass pair at a polarising angle of 56°. Find the angle of refraction in glass.
Explain how an unpolarised light gets polarised when incident on the interface separating the two transparent media.
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 ______.
The transverse nature of light is shown in ______.
Discuss polarisation by selective absorption.
What is a analyser?
State and obtain Malus’ law.
State Brewster’s law.
What is the angle of polarisation and obtain the equation for an angle of polarisation?
Mention the types of optically active crystals with example.
How is polarisation of light obtained by scattering of light?
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?
To ensure almost 100 per cent transmissivity, photographic lenses are often coated with a thin layer of dielectric material. The refractive index of this material is intermediated between that of air and glass (which makes the optical element of the lens). A typically used dielectric film is MgF2 (n = 1.38). What should the thickness of the film be so that at the center of the visible spectrum (5500 Å) there is maximum transmission.
An unpolarized light beam is incident on the polarizer of a polarization experiment and the intensity of light beam emerging from the analyzer is measured as 100 Lumens. Now, if the analyzer is rotated around the horizontal axis (direction of light) by 30° in clockwise direction, the intensity of emerging light will be ______ Lumens.
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 ______.
