JEE Main 2021 — Current Electricity Question with Solution
From: JEE Main 2021 (Online) 16th March Morning Shift
Question
A conducting wire of length 'l', area of cross-section A and electric resistivity is connected between the terminals of a battery. A potential difference V is developed between its ends, causing an electric current.
If the length of the wire of the same material is doubled and the area of cross-section is halved, the resultant current would be :
If the length of the wire of the same material is doubled and the area of cross-section is halved, the resultant current would be :
Choose an option
Show full solutionCorrect option: C
Correct answer
C
Step-by-step explanation
We know that
Now, new length :
new area of cross section :
New resistance :
Resultant current :
Now, new length :
new area of cross section :
New resistance :
Resultant current :
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This is a previous-year question from JEE Main 2021, 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.