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प्रश्न
Explain the experiment, with a neat diagram, to prove the following:
'Sound needs material medium for propagation.'
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उत्तर
Bell jar experiment can prove that sound needs material medium for its propagation.
Construction
- A bell jar
- A vacuum pump connected to the jar through a tube
- An electric bell inside the jar and is connected to the electric supply through the lid of the bell jar
Working
Initially, the vacuum pump is 'OFF' so that air is present inside the jar. Now, if the electric supply is switched on, the electric bell will start ringing and this ringing can be heard outside the bell jar.
Now, switch on the vacuum pump such that it starts sucking the air inside the jar. It will be observed that, with the decrease in the quantity of air inside the jar, the level of ringing sound heard outside also decreases. If the pump is used for a sufficiently long period, then the quantity of air inside the jar will be so low that the ringing sound outside it will not be audible. This proves that sound requires a medium for its propagation.
संबंधित प्रश्न
Fill in the blank.
Sound requires a ________ for propagation.
Name one solid, on liquid and one gas through which sound can travel.
Describe an experiment to show that sound cannot pass through vacuum.
An electric bell is suspended by thin wires in a glass vessel and set ringing. Describe and explain what happens if the air is gradually pumped out of the glass vessel.
Answer the following question :
How does the speed of sound differ in different media?
How long will sound take to travel in (a) and iron rail and (b) air, both 3.3 km in length? Take speed of sound in air to be 330 m/s and in iron to be 5280 m/s.
What is the audible range of frequency?
Can we hear sounds of frequencies:
Less than 20 Hz
Do all animals have same ranges of audible frequencies?
State three characteristics of the medium required for the propagation of sound.
