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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
If the polarising angle for a given medium is 60°, then the refractive index of the medium is.................
What is a Polaroid?
With the help of neat diagram, explain how non-polar dielectric material is polarised in external electric field of increasing intensity. Define polarisation in dielectrics.
For a glass plate as a polariser with refractive index 1.633, calculate the angle of incidence at which light is polarised.
If the critical angle of a medium is sin-1(3/5), find the polarising angle.
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°.
Show, using a simple polaroid, that light waves are transverse in nature. Intensity of light coming out of a polaroid does not change irrespective of the orientation of the pass axis of the polaroid. Explain why.
How does one demonstrate, using a suitable diagram, that unpolarised light when passed through a Polaroid gets polarised?
Using the phenomenon of polarisation, show how the transverse nature of light can be demonstrated.
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
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.
With the help of an experiment, state how will you identify whether a given beam of light is polarised or unpolarized?
Unpolarised light is incident on a polaroid. How would the intensity of transmitted light change when the polaroid is rotated?
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.
Light transmitted by Nicol prism is ______.
What is a polariser?
State and obtain Malus’ law.
State Brewster’s law.
Discuss about pile of plates.
What is normal focusing?
The reflected light is found to be plane polarised when an unpolarized light falls on a denser medium at 60° with the normal. Find the angle of refraction and critical angle of incidence for total internal reflection in the denser to rarer medium reflection.
Polarisation of light is the only phenomenon that establishes ______.
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.
