JEE Main 2019PhysicsExperimental PhysicsHardMCQ

JEE Main 2019 — Experimental Physics Question with Solution

JEE Main 2019 (10 Jan Shift 1)

Question

A potentiometer wire AB having length L and resistance 12r is joined to a cell D of emf ε and internal resistance r. A cell C having EMF ε/2 and internal resistance 3r is connected. The length AJ, at which the galvanometer, as shown in the figure, shows no deflection is

Choose an option

Show full solutionCorrect option: D
Correct answer
D1324L

Step-by-step explanation

Potential difference across AJ=I RAJ,

=ε13r·12rL·x

For no current in galvanometer,

ε2= potential difference across AJ

ε2=12ε13Lx

x=13L24

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About this question

This is a previous-year question from JEE Main 2019, covering the Experimental Physics 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.