JEE Main 2020PhysicsElectromagnetic WavesMediumMCQ

JEE Main 2020 — Electromagnetic Waves Question with Solution

JEE Main 2020 (03 Sep Shift 2)

Question

Two sources of light emit X-rays of wavelength 1 nm and visible light of wavelength 500 nm, respectively. Both the sources emit light of the same power 200 W. The ratio of the number density of photons of X-rays to the number density of photons of the visible light of the given wavelengths is:

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Show full solutionCorrect option: A
Correct answer
A1500

Step-by-step explanation

Ps-Power of source

Ps=nhcλ ; n =  no. of photons emitted/s

⇒  n∝λ  ⇒  n2n1=1/500

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About this question

This is a previous-year question from JEE Main 2020, covering the Electromagnetic Waves 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.