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Intensity through two crossed polaroids with a third polaroid between them

This type of question, asked 9 times: 4 May 2023 S1, 19 Apr 2025 S1, 21 Apr 2025 S1, 22 Apr 2025 S2, 11 Apr 2026 S1, 16 Apr 2026 S2, 17 Apr 2026 S2, 12 May 2026 S1, 15 May 2026 S2. All 9 questions below, oldest first.

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  1. Question 1

    4 May 2023 S1

    34
    Three identical polaroids P1,P2P_1, P_2 and P3P_3 are placed one after another. The pass axis of P2P_2 and P3P_3 are inclined at angles 60∘60^\circ and 90∘90^\circ with respect to axis of P1P_1. The source has intensity I0I_0. The intensity of transmitted light through P3P_3 is (cos⁡60∘=0.5,cos⁡30∘=32\cos 60^\circ = 0.5, \cos 30^\circ = \frac{\sqrt{3}}{2})

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  2. Question 2

    19 Apr 2025 S1

    43
    Three identical polaroid's P1,P2P_{1},P_{2} and P3P_{3} are placed one after another. The pass axis of P2P_{2} and P3P_{3} are inclined at an angle of 60∘60^{\circ} and 90∘90^{\circ} with respect to axis of P1P_{1}. The source has an intensity 256 W/m2256\text{ }W/m^{2}. The intensity of light at point ' O ' is (cos⁡30∘=3/2,cos⁡60∘=0.5)\left( \cos30^{\circ}=\sqrt{3}/2,\cos60^{\circ}= 0.5 \right)

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  3. Question 3

    21 Apr 2025 S1

    46
    Three polarized sheets are co-axially placed. Pass axis of polaroid 2 and 3 make 30∘30^{\circ} and 90∘90^{\circ} with pass axis of polaroid sheet. If I0I_{0} is the intensity of unpolarized light entering sheet 1 , the intensity of the emergent light through sheet 3 is
    (cos⁡30∘=3/2,cos⁡90∘=0,cos⁡60∘=1/2)\left( \cos30^{\circ}=\sqrt{3}/2,\cos90^{\circ}= 0,\cos60^{\circ}= 1/2 \right)

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  4. Question 4

    22 Apr 2025 S2

    48
    Two polaroid are placed in the path of unpolarized beam of intensity ' I0I_{0} ' such that no light is emitted from the second polaroid. If a third polaroid whose polarisation axis makes an angle ' θ\theta ' with the polarisation axis of first polaroid is placed between these polaroid's then the intensity of light emerging from the last polaroid will be

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  5. Question 5

    11 Apr 2026 S1

    141
    Two polaroid A and B placed in such a way that the pass-axis of polaroid are perpendicular to each other. Now, another polaroid C is placed between A and B bisecting angle between them. If intensity of unpolarised light is I0I_0 then intensity of transmitted light after passing through polaroid B will be

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  6. Question 6

    16 Apr 2026 S2

    142
    Three identical polaroids P1,P2P_1, P_2 and P3P_3 are placed one after another. The pass axis of P2P_2 and P3P_3 are inclined at angle of 60∘60^\circ and 90∘90^\circ with respect to axis of P1P_1. The source has an intensity I0I_0. The intensity of light finally coming out is

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  7. Question 7

    17 Apr 2026 S2

    141
    An unpolarised light of intensity 64 Wm−264\ \mathrm{Wm^{-2}} passes through three polarizers successively such that the transmission axis of last polarizer is crossed with the first. The intensity of the emerging light is 6 Wm−26\ \mathrm{Wm^{-2}}. The angle between the transmission axis of the first two polarizers is

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  8. Question 8

    12 May 2026 S1

    143
    Unpolarized light with intensity I0I_0 passes through three polaroids such that the transmission axis of the last polaroid is crossed with the first. If the intensity of emerging light is I1(I1=332I0)I_1\left(I_1 = \dfrac{3}{32}I_0\right). The angle between the first two polaroids and the angle for which the transmitted intensity is maximum are respectively {\{given, cos⁡(90)=0}\cos(90) = 0\}

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  9. Question 9

    15 May 2026 S2

    143
    Three polaroid sheets are co-axially placed such that pass axis of polaroids 22 and 33 make 30∘30^\circ and 90∘90^\circ with pass axis of sheet. If I0I_0 is the intensity of unpolarised light entering first sheet, the intensity of the emergent light through 3rd3^{rd} sheet is

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