JEE Main 2018 — Current Electricity Question with Solution
From: JEE Main 2018 (Online) 15th April Morning Slot
Question
In the given circuit all resistances are of value each. The equivalent resistance between and is :
This question includes a diagram. The text above accompanies the figure.
Choose an option
Show full solutionCorrect option: A
Correct answer
A
Step-by-step explanation
Let us assume potential at point M is X volts. Now you can see a plain wire is directly connected between point N and point M so point N will also have same potential as point M.
Similarly, a plain wire is directly connected between point N and point O so point O will also have same potential as point N.
Also, a plain wire is directly connected between point O and point P so point P will also have same potential as point O.
Now you can see point P and point M both have same potential X, so no current will flow through that path so you can remove that resistor. Similarly, as point O and point M both have same potential X, so no current will flow through that path also so you can remove that resistor too.
So new circuit becomes
RAB = R + R = 2R
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This is a previous-year question from JEE Main 2018, 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.