Polarisation

IMPORTANT

Polarisation: Overview

This topic covers concepts, such as, Experiment to Demonstrate Transverse Nature of Light,Polarisation of Light Waves,Role of Polariser etc.

Important Questions on Polarisation

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IMPORTANT

Light, from a sodium lamp, is passed through two Polaroid sheets,   P 1  and   P 2  kept one after the other. Keeping   P 1  fixed,   P 2  is rotated so that its ‘pass – axis’ can be at different angles, θ  with respect to the pass – axis of P 1 .

An experimentalist records the following data for the intensity of light coming out of   P 2  as a function of the angle θ .

S. No. 

θ(Angle between the pass -axis of the two polaroids)

10° 230° 345° 460° 590°
I (Intensity of light coming out of P2) I02 38I0 122I0 I08 0


[ I 0  = Intensity of beam falling on   P 1 ]

One of these observations is not in agreement with the expected theoretical variation of I. Identify this observation.

HARD
IMPORTANT

Two polaroids are set in crossed positions. A third polariser is placed between the two making an angle θ with the pass axis of the first polaroid. In what orientations(of third polaroid with respect to first polaroid) will the transmitted intensity be (i) minimum and (ii) maximum?

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The transverse nature of light is shown by

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A beam of unpolarized light of intensity I0 is passed through a polaroid A and then through another polaroid B which is oriented so that its principal plane makes an angle of 45°  relative to that of A. The intensity of the emergent light is:

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A light ray is incident on a glass slab. It is partially reflected and partially transmitted. Then the reflected ray is

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In an experiment of polarization by polarizers, two polarizing sheets placed are together with their axis oriented such that no light is transmitted. A third sheet is inserted between them with its transmission axis at an angle of  45°with respect to each of the other axes. The fraction of incident unpolarized light intensity transmitted by the three sheet combination is

MEDIUM
IMPORTANT

Describe an experiment to demonstrate transverse wave nature of light ?

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Which of the following correctly states the property of tourmaline crystal?

MEDIUM
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Which of the following possesses dichroism ?

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What do you mean polarization by dichroism?

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Distinguish between linearly polarised and unpolarised light.?

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What is Circular Polarization?

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What is linear polarization?

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Write definitions of plane of vibration.

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Linearly polarised light is obtained by _____ (Reflection/Refraction/Scattering/Dispersion) of light.

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Define the term "Linearly polarised light".

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A _____ is a device that allows only one half of the vibrations of the transmitted light to pass through the filter only in one plane. 

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Mention two application of polaroids.

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What do you mean by polarisation?

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The phenomenon of rotation of plane polarised light is called _____ activity.