Sound cannot travel in vacuum. Describe an experiment to demonstrate this.
Sound is a mechanical wave and needs a material medium to propagate. It cannot travel in vacuum and can be shown by the following experiment. • Take an electric bell and an airtight glass bell jar. The electric bell is suspended inside the airtight bell jar. Switch ‘ON’ the electric bell. • Now, connect the bell jar to vacuum pump. • Pump out the air from the jar, the sound becomes fainter, although the same current passes through the bell. • Pump out some more air from the jar, a very feeble sound is heard.
