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प्रश्न
What is the condition necessary for an echo to be heard distinctly?
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उत्तर
Echo is a reflected sound heard after the original sound strikes a rigid obstacle...
The conditions are-
1- The reflecting surface should have a larger reflecting surface than the wavelength of the sound
2- The minimum distance to hear the echo should be 17m in the air or as described by the formula `(Vt)/2`...
संबंधित प्रश्न
The displacement distance graph of two sound waves A and B, travelling in a medium, are as shown in the diagram below.
Study the two sound waves and compare their:
- Amplitudes
- Wavelengths
Define wave velocity term in relation to a wave.
A wave passes from one medium to another medium. Mention one property of the wave out of speed, frequency or wavelength which does not change.
State two factors on which the speed of a wave travelling in a medium depends.
Explain how is the principle of echo used by
(a) The bat during its flight at night,
(b) The dolphin to locate small fish as its prey.
Why will an echo not be heard when the distance between the source of the sound and the reflecting surface is 10 m?
State two factors on which the natural frequency of a body depends.
When a sound is made from a distance of 18 m, in front of a tall building, it is found to get repeated again. Which phenomenon is associated with this observation? Give a brief explanation of this phenomenon?
A sound wave whose frequency is 5000 Hz travels in air and then hits the water surface. The ratio of its wavelengths in water and air is ______.
Match the following:
| 1. | Stethoscope | a. | Repeated reflections |
| 2. | Echogram | b. | Multiple reflections |
| 3. | SONAR | c. | Ultrasonic waves |
| 4. | Reverberation | d. | Speed of underwater objects |
