JEE Main 2021PhysicsMechanical Properties of SolidsHardNumerical

JEE Main 2021 — Mechanical Properties of Solids Question with Solution

JEE Main 2021 (24 Feb Shift 2)

Question

A uniform metallic wire is elongated by 0.04 m when subjected to a linear force F. The elongation, if its length and diameter is doubled and subjected to the same force will be _________ cm.

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Show full solutionCorrect answer: 2
Correct answer
2

Step-by-step explanation

F=Y.A·Δll⇒Δl=FY.A.·l⇒Δl=F.lY.πr2⇒Δl∝lr2

Δl2Δl1=l2l1r1r22=2122⇒Δl2Δl1=12⇒Δl2=Δl12

=0.042=0.02 m⇒Δl2=2 cm.

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About this question

This is a previous-year question from JEE Main 2021, covering the Mechanical Properties of Solids 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.