Question

Describe the bell jar experiment to prove that sound requires a medium to propagate.

Answer 1

Bell Jar Experiment : Let us take a bell jar and suspend an electric bell in it and connect it to a battery outside the jar When the circuit is closed (switch is on) we can hear the bell ringing as the jar contains air and sound travels through this air
We then remove the air from the jar with the help of a vacuum pump connected to the bell jar Now as we close the circuit we can hardly hear any sound even though the hammer of the bell is seen striking the gong So we can conclude that sound cannot propagate in the absence of the material medium