Question Detail
Question
From a point source, if amplitude of waves at a distance r is A, its amplitude at a distance 2r will be
Correct Answer
Option C is the correct answer.
Detailed Explanation
For a point source, the amplitude decreases inversely with distance: A ∝ 1/r. So at distance 2r, the amplitude is A/2.
Hint
Amplitude ∝ 1/r for a point source.