JEE Main 2022PhysicsCurrent ElectricityEasyNumerical

JEE Main 2022 — Current Electricity Question with Solution

JEE Main 2022 (27 Jun Shift 1)

Question

A cell, shunted by a 8 Ω resistance, is balanced across a potentiometer wire of length 3 m. The balancing length is 2 m when the cell is shunted by 4 Ω resistance. The value of internal resistance of the cell will be _____ Ω.

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Show full solutionCorrect answer: 8
Correct answer
8

Step-by-step explanation

Potential difference across test battery is, ∵ V=ERR+r∝l; RR+r∝l

Therefore, we can write,  88+r44+r=32

⇒44+r=38+r  ⇒16+4r=24+3r  ⇒r=8 Ω

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About this question

This is a previous-year question from JEE Main 2022, 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.