Question

Bell jar experiment showing sound can travel in vacuum.

• A. True
• B. False

Answer 1

Answer: (B)

In the bell jar experiment, the bell jar is connected to a vacuum pump, as shown in the figure. If we press the switch you will be able to hear the bell. When the air in the jar is pumped out gradually, the sound becomes fainter, although the same current is passing through the bell. After some time when less air is left inside the bell jar, we will hear a very feeble sound. If the air is removed completely we will not be able to hear any sound. The bel jar experiment shows sound cannot travel in a vacuum.