Advertisements
Advertisements
प्रश्न
Distinguish between compression and rarefaction.
Advertisements
उत्तर
A longitudinal wave propagates by means of compressions and rarefactions.
When a vibrating object moves forward, it pushes and compresses the air in front of it creating a region of high pressure. This region is called a compression (C), as shown in Fig. This compression starts to move away from the vibrating object. When the vibrating object moves backwards, it creates a region of low pressure called rarefaction (R), as shown in Fig.

A vibrating object creating a series of compressions (C)
and rarefactions (R) in the medium
Compressions are the regions of high density where the particles of the medium come very close to each other and rarefactions are the regions of low density where the particles of the medium move away from each other.
APPEARS IN
संबंधित प्रश्न
Differentiate between a high pitch sound and a low pitch sound.
Why are musical instruments provided with more than one string ?
What type of wave is represented :
(a) by density-distance graph?
(b) by displacement-distance graph?
Name the type of waves produced when a tuning fork is struck in air.
We can distinguish between the musical sounds produced by different singers on the basis of the characteristic of sound called :
What is approximate value of the speed of sound in iron as compared to that in air? Illustrate your answer with a simple experiment.
The sound of which of the following frequency is audible to us?
2 Hz, 1000 Hz, 200 kHz, 8 MHz
Match the following
| 1. | Infrasonic | (a) | Compressions |
| 2. | Echo | (b) | 22 kHz |
| 3. | Ultrasonic | (c) | 10 Hz |
| 4. | High-pressure region | (d) | Ultrasonography |
Which of the following statements are correct?
- Sound is produced by vibrations.
- Sound requires a medium for propagation.
- Light and sound both require a medium for propagation.
- Sound travels slower than light.
Name two musical instruments which produce sound by vibrating strings.
