InterviewSolution
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InterviewSolution
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A bat emits ultrasonic sound of frequency 100 kHz in air. If this sound meets a water surface, the wavelengths of the reflected and transmitted sound are (Speed of sound in air = 340 m `s^(-1)` and in water = 1500 m `s^(-1)` )A. `3.4mm,30mm`B. 6.8 mm, 15 mmC. 3.4 mm, 15 mmD. 6.8 mm, 30 mm |
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Answer» Correct Answer - C Here, `upsilon=100kHz=100xx10^(3)`Hz `=10^(5)Hz=10^(5)s^(-1)` `v_(a)=340ms^(-1),v_(w)=1500 ms^(-1)` Frequency of both the reflected and transmitted sound remains unchanged. Wavelength of reflected sound. `lamda_(a)=(v_(a))/upsilon=(340 ms^(-1))/(10^(5)s^(-1))=34xx10^(-4)m` `=3.4xx10^(-3)m=3.4 mm` Wavelength of transmitted sound, `lamda_(w)=(v_(w))/(upsilon)=(1500ms^(-1))/(10^(5)s^(-1))=15xx10^(-3)m=15 mm` |
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