JEE Main 2020PhysicsWave OpticsMediumMCQ

JEE Main 2020 — Wave Optics Question with Solution

JEE Main 2020 (02 Sep Shift 2)

Question

In a Young's double slit experiment,16 fringes are observed in a certain segment of the screen when light of wavelength 700 nm is used. If the wavelength of light is changed to 400 nm, the number of fringes observed in the same segment of the screen would be :

Choose an option

Show full solutionCorrect option: D
Correct answer
D28

Step-by-step explanation

y=m1Dλ1d=mDλ2d
m2m1=λ1λ2⇒m2=700400×16=28

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 2020, 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.