Wave Optics · JEE Main previous year questions

2023 13 questions

1. Q402023 · 13 Apr 2023 · Shift 2

   In a Young's double slits experiment, the ratio of amplitude of light coming from slits is $2:1$. The ratio of the maximum to minimum intensity in the interference pattern is:

   1. A.$25:9$
   2. B.$9:1$
   3. C.$9:4$
   4. D.$2:1$
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   Answer: B

2. Q552023 · 10 Apr 2023 · Shift 1· Numerical answer

   Unpolarised light of intensity $32{\text{ Wm}}^{-2}$ passes through the combination of three polaroids such that the pass axis of the last polaroid is perpendicular to that of the pass axis of first polaroid. If intensity of emerging light is $3{\text{ Wm}}^{-2}$, then the angle between pass axis of first two polaroids is _________${}^{\circ }$.

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   Answer: 30 or 60

3. Q432023 · 10 Apr 2023 · Shift 2

   The ratio of intensities at two points P and Q on the screen in a Young's double slit experiment where phase difference between two waves of same amplitude are $\pi /3$ and $\pi /2$, respectively are

   1. A.$2:3$
   2. B.$1:3$
   3. C.$3:1$
   4. D.$3:2$
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   Answer: D

4. Q452023 · 8 Apr 2023 · Shift 2

   The width of fringe is $2\mathrm{mm}$ on the screen in a double slits experiment for the light of wavelength of $400\mathrm{nm}$. The width of the fringe for the light of wavelength $600\mathrm{nm}$ will be:

   1. A.$4\mathrm{mm}$
   2. B.$1.33\mathrm{mm}$
   3. C.$2\mathrm{mm}$
   4. D.$3\mathrm{mm}$
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   Answer: D

5. Q602023 · 6 Apr 2023 · Shift 2· Numerical answer

   A beam of light consisting of two wavelengths $7000\text{ A˚}$ and $5500\text{ A˚}$ is used to obtain interference pattern in Young's double slit experiment. The distance between the slits is $2.5\text{ mm}$ and the distance between the plane of slits and the screen is $150\text{ cm}$. The least distance from the central fringe, where the bright fringes due to both the wavelengths coincide, is $n\times 10^{-5}\text{ m}$. The value of $n$ is ___________.

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   Answer: 462

6. Q322023 · 1 Feb 2023 · Shift 1

   '$n$' polarizing sheets are arranged such that each makes an angle $45^{\circ }$ with the preceding sheet. An unpolarized light of intensity I is incident into this arrangement. The output intensity is found to be $I/64$. The value of $n$ will be:

   1. A.4
   2. B.5
   3. C.3
   4. D.6
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   Answer: D

7. Q392023 · 31 Jan 2023 · Shift 1

   Two polaroids $\mathrm{A}$ and $\mathrm{B}$ are placed in such a way that the pass-axis of polaroids are perpendicular to each other. Now, another polaroid $\mathrm{C}$ is placed between $\mathrm{A}$ and $\mathrm{B}$ bisecting angle between them. If intensity of unpolarized light is $I_0$ then intensity of transmitted light after passing through polaroid $\mathrm{B}$ will be:

   1. A.$\frac{I_0}{4}$
   2. B.$\frac{I_0}{8}$
   3. C.Zero
   4. D.$\frac{I_0}{2}$
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   Answer: B

8. Q482023 · 31 Jan 2023 · Shift 1

   Given below are two statements : One is labelled as Assertion A and the other is labelled as Reason R Assertion A : The beam of electrons show wave nature and exhibit interference and diffraction. Reason R : Davisson Germer Experimentally verified the wave nature of electrons. In the light of the above statements, choose the most appropriate answer from the options given below :

   1. A.A is not correct but R is correct.
   2. B.Both A and R are correct and R is the correct explanation of A
   3. C.Both A and R are correct but R is Not the correct explanation of A
   4. D.A is correct but R is not correct
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   Answer: B

9. Q532023 · 31 Jan 2023 · Shift 2· Numerical answer

   Two light waves of wavelengths $800$ and $600\text{ nm}$ are used in Young's double slit experiment to obtain interference fringes on a screen placed $7\text{ m}$ away from plane of slits. If the two slits are separated by $0.35\text{ mm}$, then shortest distance from the central bright maximum to the point where the bright fringes of the two wavelength coincide will be ___________ mm.

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   Answer: 48

10. Q542023 · 30 Jan 2023 · Shift 1· Numerical answer
    
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    Answer: 10

11. Q422023 · 29 Jan 2023 · Shift 1
    
    1. A.0.2 mm
    2. B.0.5 mm
    3. C.0.4 mm
    4. D.0.1 mm
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    Answer: A

12. Q572023 · 29 Jan 2023 · Shift 2· Numerical answer

    Unpolarised light is incident on the boundary between two dielectric media, whose dielectric constants are 2.8 (medium $-1$) and 6.8 (medium $-2$), respectively. To satisfy the condition, so that the reflected and refracted rays are perpendicular to each other, the angle of incidence should be ${\tan }^{-1}{\left(1+\frac{10}{\theta }\right)}^{\frac{1}{2}}$ the value of $\theta$ is __________. (Given for dielectric media, ${\mu }_r=1$)

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    Answer: 7

13. Q362023 · 25 Jan 2023 · Shift 1

    In Young's double slits experiment, the position of $5^{\mathrm{th}}$ bright fringe from the central maximum is 5 cm. The distance between slits and screen is 1 m and wavelength of used monochromatic light is 600 nm. The separation between the slits is :

    1. A.$60\mu \mathrm{m}$
    2. B.$48\mu \mathrm{m}$
    3. C.$36\mu \mathrm{m}$
    4. D.$12\mu \mathrm{m}$
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    Answer: A