Question

an electric bell is kept under a bell jar in which a vacuum has been created slowly air is introduced in to the jar. what will happed to the sound of electric bell?

Answer 1

It will increase until it reaches its maximum.

Answer 2

It will increase

Step-by-step explanation:

Sound wave needs a medium to travel. Till the time there is vacuum in the jar the sound waves will not be heard. This is the reason why we can't hear in space.

When the air is introduced into the jar, there will be medium in which the sound waves can travel. Slowly you will be able to hear the sound and it will keep on increasing until the jar is completely filled with air.