JEE Main 2026 · PhysicsMultiple choiceSingle correctEasyApplication

JEE Main 5 April 2026, Shift 1, Physics Q39

Question 39 of 75 in this shift, Physics question 14 of 25, Section A.

In Young's double slit experiment, the fringe width of the interference pattern produced on the screen is

2.4\ \mu

m. If the experiment is carried out in another medium having refractive index 1.2, the fringe width will be ____

\mu

(1)1.2
(2)2Official answer
(3)2.4
(4)2.88

Official answer

Option 2

NTA final key.

Chapter: Wave Optics
Topic: Young's Double Slit
Idea tested: Effect of Medium on Fringes

Same topic in other shifts

All Young's Double Slit questions

2 Apr 2026, Shift 2 · Q46In a Young's double slit experiment, the intensity at some point on the screen is found to be $\frac{3}{4}$ times of the maximum of the…MediumNumerical value
4 Apr 2026, Shift 2 · Q50In a double slit experiment, when one of the slits is covered by a transparent mica sheet of refractive index 1.56, the central fringe…MediumNumerical value
5 Apr 2026, Shift 2 · Q42The maximum intensity in a Young's double slit experiment is $I_0$ . Distance between the slits ( $d$ ) is $5\lambda$ , where $\lambda$ is the…MediumSingle correct
6 Apr 2026, Shift 1 · Q36In interference experiment the path difference between two interfering waves at a point $A$ on the screen is $\lambda/3$ , where $\lambda$ …EasySingle correct
6 Apr 2026, Shift 2 · Q45In a Young double slit experiment, the wavelength of incident light is 6000 Å, the separation between slits $S_1$ and $S_2$ is 5 cm and…MediumDiagram basedHas a figure
3 Apr 2025, Shift 1 · Q50Two coherent monochromatic light beams of intensities 4I and 9I are superimposed. The difference between the maximum and minimum…EasyNumerical value

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 42 of the 174 JEE Main shifts held from 2017 to 2026.