JEE Main 2020PhysicsCurrent ElectricityMediumMCQ

JEE Main 2020 — Current Electricity Question with Solution

JEE Main 2020 (08 Jan Shift 1)

Question

The length of a potentiometer wire is 1200 cm and it carries a current of 60 mA For a cell of emf 5 V and internal resistance of 20 Ω the null point on it is found to be at 1000 cm The resistance of whole wire is:

Choose an option

Show full solutionCorrect option: D
Correct answer
D100Ω

Step-by-step explanation


Potential gradient =51000=VP1200
VP=6 V
And RP=VPI=660×10-3=100 Ω

Practice this on the real CBT interface

Solve this JEE Main question (and the rest of the Current Electricity chapter) on PrepSharp's TCS iON-style CBT player — with timer, bookmarks and session analytics.

Solve interactively →

About this question

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.