When the object making the sound is moving towards you, the frequency goes up…
2013
When the object making the sound is moving towards you, the frequency goes up due to the waves getting pushed more tightly together. The opposite happens when the object moves away from you and the pitch goes down. This phenomenon is called _____.
- A.
Band width
- B.
Doppler effect
- C.
Sound refraction
- D.
Vibrations
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Correct answer: B
Doppler effect (Doppler shift): The change in frequency (pitch) of a wave observed when the source and the observer move relative to each other. When the source moves towards the observer, the waves are compressed and the observed frequency increases (pitch goes up). When the source moves away, the waves are stretched and the observed frequency decreases (pitch goes down). Example: An ambulance siren sounds higher in pitch as it approaches and lower as it recedes. डॉप्लर प्रभाव (Doppler Effect): जब स्रोत और प्रेक्षक के बीच आपेक्षिक गति होती है तो प्रेक्षक द्वारा महसूस की जाने वाली तरंग की आवृत्ति (पिच) बदल जाती है। स्रोत प्रेक्षक की ओर आने पर आवृत्ति बढ़ती है; दूर जाने पर आवृत्ति घटती है। इस प्रश्न का सही उत्तर है: Doppler effect