JEE Main 2020 — Current Electricity Question with Solution
From: JEE Main 2020 (Online) 3rd September Morning Slot
Question
Model a torch battery of length to be made up
of a thin cylindrical bar of radius ‘a’ and a
concentric thin cylindrical shell of radius ‘b’
filled in between with an electrolyte of
resistivity (see figure). If the battery is
connected to a resistance of value R, the
maximum Joule heating in R will take place for :
This question includes a diagram. The text above accompanies the figure.
Choose an option
Show full solutionCorrect option: C
Correct answer
C
Step-by-step explanation
Internal resitance of battery
r =
Power in external resistance PR =
Maximum Power in external resistance is generated when it is equal to internal resistance of battery. So PR is maximum when r = R.
R =
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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.