Table of Contents
What happens in the bell jar experiment?
The candle was initially lit, and then the bell jar placed over the two items, and once the oxygen had been consumed by the candle, the flame extinguished. However, the candle was able to be reignited a number of days later, demonstrating that the plant had produced the oxygen required.
Why can’t the bell be heard when the air is vacuumed out of the jar?
As the pressure inside the bell jar drops, there is less and less air to carry the sound wave, and the ringing of the bell becomes softer and softer, until there is so little air in the bell jar that the sound wave has no medium in which to propagate, and you and the class cannot hear the ringing of the bell.
When the vacuum pump removes the air what happens to the sound?
Once a vacuum pump is turned on, the air is slowly removed. As this happens, the sound gets quieter until eventually it cannot be heard at all.
What would be happened as air was pumped out of the jar and the electric bell rang?
As the air in the jar is being pumped out, the sound becomes fainter, although it is the same current that is passing through the bell. On reducing the air pressure further, the intensity of the sound reduces and stops.
Can sound travel through a vacuum?
Sound does not travel at all in space. The vacuum of outer space has essentially zero air. Because sound is just vibrating air, space has no air to vibrate and therefore no sound. If you are sitting in a space ship and another space ship explodes, you would hear nothing.
What happens to sound in a vacuum?
What would the student observe if air was pumped out of the jar while the electric bell was ringing?
The bell starts ringing and you can hear its sound clearly. Now, pump out the air from the bell jar gradually by switching on the vacuum pump attached in it. ► Observation : You will notice as more and more air is removed from the bell jar, the sound of the bell becomes fainter and fainter.
What happens as the air is removed from the jar?
for its propagation. As the air is pumped out of the sealed bell jar, the sound from the bell jar fades, because the medium is being removed, thus the intensity of sound decreases.
What happens to sound in vacuum?
What happens when air is pumped out of the jar?
As the air is pumped out of the sealed bell jar, the sound from the bell jar fades, because the medium is being removed, thus the intensity of sound decreases. Was this answer helpful?
What is sound and how it is produced 9th?
Sound is defined as vibrations that travel through the air or another medium as an audible mechanical wave. It is produced from a vibrating body. The vibrating body causes the medium (water, air, etc.) around it to vibrate thus producing sound.
How does a vacuum pump work in a bell jar?
A bell jar is placed on a base which is vented to a hose fitting that can be connected via a hose to a vacuum pump. By pumping the air out of the bell jar, the air pressure inside the jar can be varied. How does the experiment work? The experiment is done by placing an electrical bell in the bell jar.
What is the Bell Jar Experiment used for?
The bell jar experiment is a common experiment used to demonstrate that sound needs a medium to travel. What is a bell jar? A bell jar is a laboratory equipment used for creating a vacuum.
What happens when a bell is placed in a vacuum?
The experiment is done by placing an electrical bell in the bell jar. As the air is pumped out of the sealed bell jar, the sound from the bell jar fades. At a particular vacuum, no more sound is heard from the bell, but we can see that the hammer continues hitting the gong and sound is produced.
How do you use a vacuum pump in a real lab?
(a) As performed in a real lab: 1 Arrange the apparatus as shown in the figure. 2 Connect the electric bell and the vacuum pump to the air tight glass bell jar. 3 Insert key to complete the circuit. 4 Reduce the air pressure inside the chamber by pumping out the air through the vacuum pump.