JEE Main 2021ChemistryStructure of AtomEasyNumerical

JEE Main 2021 — Structure of Atom Question with Solution

JEE Main 2021 (25 Jul Shift 2)

Question

An accelerated electron has a speed of 5×106 ms-1 with an uncertainty of 0.02%. The uncertainty in finding its location while in motion is x×10-9 m.
The value of x is __________. (Nearest integer)

[Use mass of electron=9.1×10-31 kg,

h=6.63×10-34Js,π=3.14

Enter your answer

Show full solutionCorrect answer: 58
Correct answer
58

Step-by-step explanation

Δv=0.02100×5×106=103 m s-1

Δx·Δv=h4πm

x×10-9×103=6.63×10-344×3.14×9.1×10-31

x×10-9×103=0.058×10-3

x=0.058×10-610-9=58

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About this question

This is a previous-year question from JEE Main 2021, covering the Structure of Atom chapter of Chemistry. 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.