Question:
A sound source, emitting sound of constant frequency, moves with a constant speed and crosses a stationary observer. The frequency \(n\) of sound heard by the observer is plotted against time \(t\). Which of the following graphs represents the correct variation?
A sound source, emitting sound of constant frequency, moves with a constant speed and crosses a stationary observer. The frequency \(n\) of sound heard by the observer is plotted against time \(t\). Which of the following graphs represents the correct variation?
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Doppler effect gives constant frequency for constant speed, with a sudden change at crossing.
Updated On: Mar 24, 2026
- Graph (a)
- Graph (b)
- Graph (c)
- Graph (d)
Show Solution
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The Correct Option is D
Solution and Explanation
Step 1: When the source approaches, frequency heard is higher and constant.
Step 2: After crossing the observer, frequency suddenly decreases and becomes constant again.
Step 3: Hence, frequency shows a sudden drop at the instant of crossing.
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