NEET
- Exam
- NEET
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- Physics
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- Waves and Sound
NEET · Physics · Waves and Sound
A railway engine whistling at a constant frequency moves with a...
A railway engine whistling at a constant frequency moves with a constant speed. It goes past a stationary observer standing beside the railway track. The frequency of the sound by the observer is plotted against time . Which of the following best represents the resulting curve?
Options
- A
- B
- C
- D
Correct answer
D.
Step-by-step solution
When the engine approaches the observer,
(f_1=f\left(\frac{v}{v-v_s}\right)>f \text{ but constant. })
When it moves away from the source,
(f_2=f\left(\frac{v}{v+v_s}\right) < f \text{ but constant. })