EASY
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A beam of unpolarised 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 emergent light is :

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Important Questions on Wave Optics

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When an unpolarized light of intensity I0 is incident on a polarizing sheet, the intensity of light which does not get transmitted is
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A beam of light falls on a system of 4 polaroids, which are arranged in succession, such that the axis of each polaroids makes 30° with the axis of the preceding one. The fraction of the intensity of the incident light that passes through the system is
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In a stạck of three polarising sheets, the first and the third are crossed while the middle one has its axis at 45° to the axes of the other two. The fraction of intensity of an incident unpolarised beam of light that is transmitted by the stack is
MEDIUM
A ray of light travelling in impure water is incident on a glass plate immersed in it. When the angle of incidence is 51°, the reflected ray is totally plane polarized. Given that refractive index of impure water is 1.4. The refractive index of glass should be _____ tan51°=1.235
HARD
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 needs to be rotated further, to reduce the output intensity to zero, is
HARD
  Column I   Column II
(i) Interference (P) Coherent sources
(ii) Brewster's Law (Q) μ=1sinC
(iii) Malus Law (R) μ=tanθp
(iv) Total Internal reflection (S) I=I0cos2θ
HARD

Unpolarised red light is incident on the surface of a lake at incident angle θR. An observer seeing the light reflected from the water surface through a polariser notices that on rotating the polariser, the intensity of light drops to zero at a certain orientation. The red light is replaced by unpolarised blue light. The observer sees the same effect with reflected blue light at incident angle θB.

Then,

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A source of light is placed in front of a screen. The intensity of light on the screen is I. Two Polaroids P1 and P2 are so placed in between the source of light and screen that the intensity of light on the screen is I2. Then the P2, should be rotated by an angle of (degrees) so that the intensity of light on the screen becomes 3I8.
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A transparent medium shows relation i and r as shown. If the speed of light in vacuum is c, the Brewster angle for the medium is

Question Image 

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The Brewsters angle ib for an interface should be
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If θ is the polarising angle for two optical media whose critical angles are C1 and C2, then the correct relation is
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The polarising angle for transparent medium is θ, v is the speed of light in that medium. Then the relation between θ and v is (c= velocity of light in air)
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The refractive index  n ' and the polarizing angle ' θp ' of a medium are related as
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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.
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Light waves are transverse in nature, which is due to the property of
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Ordinary (i.e. unpolarised) light is incident on the surface of a transparent material at the polarising angle. If it is partly reflected and partly refracted, what is the angle between the reflected and the refracted rays ?
HARD
Show using a proper diagram how unpolarized light can be linearly polarised by reflection from a transparent glass surface.
MEDIUM
A ray of unpolarised light is incident on the glass surface of refractive index 1.73 at polarizing angle. The angle of refraction will be [Take tan60°=1.73 ]
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Two Polaroids P1 and P2 are placed with their axis perpendicular to each other. Unpolarised light with intensity I0  is incident on P1. A third polaroid P3 is kept in between P1 and P2 such that its axis makes an angle 45o with that of P1. The intensity of transmitted light through P2 is
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Unpolarized light of intensity I0 is incident on surface of a block of glass at Brewster's angle. In that case, which one of the following statements is true?