Advertisements
Advertisements
प्रश्न
High-frequency sounds that cannot be heard by you are called _______.
Advertisements
उत्तर
High-frequency sounds that cannot be heard by you are called Ultrasonic.
APPEARS IN
संबंधित प्रश्न
Select the correct alternative :
We can hear sound of frequency
Which of the following can produce longitudinal waves as well as transverse waves under different conditions?
In an experiment, Anhad studies sound waves. He sets up a loudspeaker to produce sound as shown below :
Anhad adjusts the signal to the loudspeaker to give a sound of frequency 200 Hz.
(a) What happens to the air in-between Anhad and the loudspeaker ?
(b) Explain how Anhad receives sound in both ears.
'Note' is a sound :
What is sound? How is it produced?
A cannon is fired at A (see diagram). An observer at B hears two sounds. The first sound is heard after 1 second and the second 3s after the observer sees the flash. (Velocity of sound = 340 ms−1)
(i) Why does the observer see the flash before he hears the sound?
(ii) Calculate the distance x between the observer and the wall.
The wavelength of the vibrations produced on the surface of water is 2 cm. If the wave velocity is 16 ms-1, calculate:
- no. of waves produced in one second
- time required to produce one wave.
Explain how the principle of echo is used by
The bat during its flight at night
Match the following.
| Ultrasonics | Frequency below 20Hz |
| Speed of sound in air | Needs material medium |
| Infrasonics | 330ms-1 |
| Sound propagation | Frequency more than 20000 Hz |
