GK
BIG BANG THEORY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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lower
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higher
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Either A or B
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None of the above
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Detailed explanation-1: -First, the sound increases in loudness as the ambulance approaches and decreases in loudness as it moves away, which is expected. But in addition, the high-pitched siren shifts dramatically to a lower-pitched sound.
Detailed explanation-2: -When the ambulance passes you, the sound becomes lower in pitch. Behind the ambulance there are fewer vibrations per second, and a lower sound is heard. This change in pitch is known as the Doppler Effect.
Detailed explanation-3: -You may have noticed that as a fast moving siren passes by you, the pitch of the siren abruptly drops in pitch. At first, the siren is coming towards you, when the pitch is higher. After passing you, the siren is going away from you and the pitch is lower. This is a manifestation of the Doppler effect.
Detailed explanation-4: -When an ambulance passes with its siren blaring, you hear the pitch of the siren change: as it approaches, the siren’s pitch sounds higher than when it is moving away from you. This change is a common physical demonstration of the Doppler effect.