JEE Main 2026 — Waves and Sound Question with Solution
JEE Main 2026 (24 January Shift 2)
Question
A point source is kept at the center of a spherically enclosed detector. If the volume of the detector increased by 8 times, the intensity will
Choose an option
Show full solutionCorrect option: C
Correct answer
Cdecrease by 4 times
Step-by-step explanation
For a point source, intensity is given by where is power and is distance.
If the volume of the spherical detector increases by 8 times, then , giving .
The new intensity is .
Therefore intensity decreases by 4 times.
If the volume of the spherical detector increases by 8 times, then , giving .
The new intensity is .
Therefore intensity decreases by 4 times.
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This is a previous-year question from JEE Main 2026, covering the Waves and Sound 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.