JEE Main 2020 — Current Electricity Question with Solution
From: JEE Main 2020 (Online) 8th January Morning Slot
Question
The length of a potentiometer wire is 1200 cm
and it carries a current of 60 mA. For a cell of
emf 5V and internal resistance of 20, the null
point on it is found to be a 1000 cm. The
resistance of whole wire is :
Choose an option
Show full solutionCorrect option: D
Correct answer
D100
Step-by-step explanation
Let Resistance per unit length of potentiometer wire =
5 = 1000 60 10-3
=
Resistance of potentiometer wire = 1200 = 100
5 = 1000 60 10-3
=
Resistance of potentiometer wire = 1200 = 100
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This is a previous-year question from JEE Main 2020, 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.