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प्रश्न
Explain how the principle of echo is used by
The bat during its flight at
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उत्तर
Bats can produce and detect the sound of very high frequency. The bats fly with speed much lower than the speed of sound. The sounds produced by flying bats get reflected from any obstacle in front of it. By hearing the echoes, bats come to know where the obstacles are, even in the dark. So, they can fly safely without colliding with the obstacles. This process of detecting obstacles is called sound ranging.
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संबंधित प्रश्न
A certain sound has a frequency of 256 hertz and a wavelength of 1.3 m.
1) Calculate the speed with which this sound travels
2) What difference would be felt by a listener between the above sound and another sound traveling at the same speed, but of wavelength 2.6 m?
Name the waves which are used in sonar to find the depth of a sea. Give one reason for their use.
Mention two properties of a wave, one property which varies and the other which remains constant when the wave passes from one medium to another.
What is meant by echo depth sounding?
Why will an echo not be heard when the distance between the source of the sound and the reflecting surface is 10 m?
(i) A man stands at a distance of 68 m from a cliff and fires a gun. After what time interval will he hear the echo, if the speed of sound in air is 340 ms−1?
(ii) If the man had been standing at a distance of 12 m from the cliff would he have heard a clear echo?
Explain reflection at the boundary of a rarer medium.
Write short notes on reflection of sound waves from plane and curved surfaces.
