JEE Main 2019 — Current Electricity Question with Solution
From: JEE Main 2019 (Online) 12th January Morning Slot
Question
An ideal battery of 4 V and resistance R are connected in series in the primary circuit of a potentiometer of length 1 m and esistance 5 . The value of R, to give a potential difference of 5 mV across 10 cm of potentiometer wire, is :
Choose an option
Show full solutionCorrect option: D
Correct answer
D395
Step-by-step explanation
Let current flowing in the wire is i.
i =
If resistance of 10 m length of wire is x
then x = 0.5 = 5
V = P.d. on wire = i. x
5 103 = .(0.5)
= 102
or R + 5 = 400
R = 395
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This is a previous-year question from JEE Main 2019, 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.