CBSE Science Class 8
Sound
Sound - Chapter Wise CBSE Solved Question and Answer Based On NCERT
Points To Remember:
- Sound is a sequence of waves of pressure that propagates through compressible media such as air or water
- Sound is produced by vibrating objects
- Sound helps us to communicate with one another, we can hear a variety of sounds in our surrounding
- The to and fro and back and forth motion of an object is called vibration
- In human sound is produced by the voice box or larynx.
- Sound always need a medium either solid, liquid or gas to travel, it cannot travel through vacuum.
- In human body eardrum senses the vibrations of sound, it sends the signals to the brain and this process is called hearing
- The total number of vibrations or oscillations per second is called frequency of oscillation, which is expressed in hertz
- Sound depends upon the amplitude of vibration, larger the amplitude of vibration the louder is the sound
- Higher the frequency of vibration, the higher is the pitch and shriller is the sound
- Unpleasant sounds are called noise, we should made attempts to minimise noise pollution as it is harmful for human beings
