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MHT CET 2025 (25 Apr, Shift 2) · Doppler Effect

Doppler Effect question from MHT CET 2025 (25 Apr, Shift 2)

Q9MHT CET 2025 · 25 APR · SHIFT 2Easy

Doppler Effect

At what speed should a source of sound move so that the observer finds the apparent frequency equal to half the original frequency?

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Answer: (d)

A lower frequency means the source moves away: $n' = n\frac{V}{V + v_s}$ .
$\frac{n}{2} = n\frac{V}{V + v_s} \Rightarrow V + v_s = 2V$
$v_s = V$ , moving away from the observer. So the answer is (d) V.

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