JEE Advanced Previous Year Questions (2018 - 2023): Wave Optics | Physics for JEE Main & Advanced PDF Download

2022

Q1: A double slit setup is shown in the figure. One of the slits is in medium 2 of refractive index n₂. The other slit is at the interface of this medium with another medium 1 of refractive index n1( ≠ n₂). The line joining the slits is perpendicular to the interface and the distance between the slits is d. The slit widths are much smaller than d. A monochromatic parallel beam of light is incident on the slits from medium 1. A detector is placed in medium 2 at a large distance from the slits, and at an angle θ from the line joining them, so that θ equals the angle of refraction of the beam. Consider two approximately parallel rays from the slits received by the detector.

Which of the following statement(s) is(are) correct?
(a) The phase difference between the two rays is independent of d.
(b) The two rays interfere constructively at the detector.
(c) The phase difference between the two rays depends on n₁ but is independent of n₂.
(d) The phase difference between the two rays vanishes only for certain values of d and the angle of incidence of the beam, with θ being the corresponding angle of refraction.     [JEE Advanced 2022 Paper 2]
Ans: (a) & (b)

Path difference in vacuum 

2020

Q1: A parallel beam of light strikes a piece of transparent glass having cross section as shown in the figure below. Correct shape of the emergent wavefront will be (figures are schematic and not drawn to scale)(a)
(b)
(c)
(d)
Ans: (a)
Clearly middle part of glass is diverging and upper and lower part are conversing so correct shape of the emergent wavefront is as shown in the figure.

2019

Q1: In a Young's double slit experiment, the slit separation d is 0.3 mm and the screen distance D is 1 m. A parallel beam of light of wavelength 600 nm is incident on the slits at angle α as shown in figure.