JEE Main 2020 · PhysicsNumerical answerNumerical valueMediumCalculation

JEE Main 5 September 2020, Shift 1, Physics Q25

Question 25 of 75 in this shift, Physics question 25 of 25.

A beam of electrons of energy E scatters from a target having atomic spacing of 1Å. The first maximum intensity occurs at

\theta = 60°

. Then E (in eV) is __________. (Planck constant h =

6.64\times10^{-34}

Js, 1 eV =

1.6\times10^{-19}

J, electron mass m =

9.1\times10^{-31}

kg)

Official answer

50.00 to 51.00

NTA final key (Sep 2020). Any value in the range scored.

Chapter: Dual Nature of Radiation and Matter
Topic: Matter Waves
Idea tested: Bragg's Law in Electron Diffraction

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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 108 of the 174 JEE Main shifts held from 2017 to 2026.