PUMPA - SMART LEARNING

எங்கள் ஆசிரியர்களுடன் 1-ஆன்-1 ஆலோசனை நேரத்தைப் பெறுங்கள். டாப்பர் ஆவதற்கு நாங்கள் பயிற்சி அளிப்போம்

Book Free Demo
Take a metal glass tumbler. Make sure that it is dry. Place a cell phone in it. (Remember that the cell phone must not be kept in water.) Ask your friend to give a ring on this cell phone from another cell phone. Listen to the ring carefully.
  
Now, surround the rim of the tumbler with your hands. Put your mouth on the opening between your hands. Indicate to your friend to give a ring again. Listen to the ring while sucking air from the tumbler. Does the sound become fainter as you suck air?
  
Remove the tumbler from your mouth. Does the sound become loud again?
 
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When we place a cell phone in a dry tumbler and give it a ring, we  a ringing sound because there is air in the tumbler.
 
When we try to suck air in, we notice that sound gets  it did earlier. As we keep sucking the air, the sound becomes .
 
So, for sound to move, a medium .
Important!
This is an activity-based exercise. Do the activity and answer questions.