JEE Main 2017PhysicsCurrent ElectricityEasyMCQ

JEE Main 2017 — Current Electricity Question with Solution

JEE Main 2017 (09 Apr Online)

Question

A uniform wire of length l and radius r has a resistance of 100 Ω . It is recast into a wire of radius r2. The resistance of new wire will be-

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Show full solutionCorrect option: A
Correct answer
A1600 Ω

Step-by-step explanation

R=ρlA
Al=V
R=ρVA2
ρ→ constant
V→ constant
R∝1A2 ∝1r22
R∝1r4
R2=16R1=1600 Ω

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About this question

This is a previous-year question from JEE Main 2017, covering the Current Electricity 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.