JEE Main 2023PhysicsWave OpticsMediumMCQ

JEE Main 2023 — Wave Optics Question with Solution

JEE Main 2023 (29 Jan Shift 1)

Question

In a Young’s double slit experiment, two slits are illuminated with a light of wavelength 800 nm. The line joining A1P is perpendicular to A1A2 as shown in the figure. If the first minimum is detected at P, the value of slits separation a will be :

The distance of screen from slits D=5 cm.

Choose an option

Show full solutionCorrect option: C
Correct answer
C0.2 mm

Step-by-step explanation

The position of first minima is

y=λD2×a(y is height of the point from the axis passing through the mid-point of A1 and A2)

Since the first minima is in front of the slit as shown in the figure,

λD2×a=a2

⇒a=λD=800×10-9×5×10-2=2×10-4 m=0.2 mm

Practice this on the real CBT interface

Solve this JEE Main question (and the rest of the Wave Optics chapter) on PrepSharp's TCS iON-style CBT player — with timer, bookmarks and session analytics.

Solve interactively →

About this question

This is a previous-year question from JEE Main 2023, covering the Wave Optics chapter of Physics. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.