JEE Main 2021PhysicsMechanical Properties of SolidsEasyMCQ

JEE Main 2021 — Mechanical Properties of Solids Question with Solution

JEE Main 2021 (26 Feb Shift 2)

Question

The length of metallic wire is l1 when tension in it is T1. It is l2 when the tension is T2. The original length of the wire will be :

Choose an option

Show full solutionCorrect option: C
Correct answer
CT2l1-T1l2 T2-T1

Step-by-step explanation

Assuming Hooke's law to be valid

T∝Δℓ

T=kΔℓ

Let,ℓ0= natural length (original length) ⇒T=kℓ-ℓ0

so, T1=kℓ1-ℓ0 & T2=kℓ2-ℓ0

⇒T1T2=ℓ1-ℓ0ℓ2-ℓ0

⇒ℓ0=T2ℓ1-T1ℓ2 T2-T1

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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.