JEE Main 2020PhysicsWave OpticsHardMCQ

JEE Main 2020 — Wave Optics Question with Solution

JEE Main 2020 (06 Sep Shift 1)

Question

In the figure below, P and Q are two equally intense coherent sources emitting radiation of wavelength 20m. The separation between P and Q is 5m and the phase of P is ahead of that of Q by 90°.A,B and C are three distinct point of observation, each equidistant from the midpoint of PQ. The intensities of radiation at A,B,C will be in the ratio :

  

Choose an option

Show full solutionCorrect option: B
Correct answer
B2:1:0

Step-by-step explanation

ΔPA=π2×202π-5=0   so ΔϕA=0

ΔPB=π2×202π=5   so ΔϕB=π2

ΔPC=5+5=10   so ∆ϕc=π

I=locos2Δϕ2

 so IA=I0

IB=I02

 Ic =0

so  IA :IB:IC=2:1:0

 

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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.