SELECT * FROM question_mgmt as q WHERE id=4260 AND status=1 SELECT id,question_no,question,chapter FROM question_mgmt as q WHERE courseId=8 AND subId=16 AND chapterId=192 and ex_no='11' AND status=1 ORDER BY CAST(question_no AS UNSIGNED) CBSE Free NCERT Solution of 9th science Sound explain how the human ear works

Question:

Explain how the human ear works.

Answer:

Different sounds produced in our surroundings are collected by pinna. The collected sound passes through the auditory canal. At the end of the auditory canal, there is a thin membrane called the eardrum or tympanic membrane. When compression the medium reaches the eardrum the pressure on the outside of the membrane increases and force the eardrum inward. Similarly, the eardrum moves outward when the rarefaction reaches it. The eardrum starts vibrating back and forth rapidly when the sound waves fall on it. The vibrating eardrum sets the small bone hammer into vibration. The vibrations are passed from the hammer to the second bone anvil, and finally to the third bone stirrup. The vibrating stirrup strikes on the membrane of the oval window and passes its vibration to the liquid in the cochlea. This produces electrical impulses in nerve cells. The auditory nerve carries these electrical impulses to the brain. These electrical impulses are interpreted by the brain as sound and we get a sensation of hearing.


SELECT ex_no,question,question_no,id,chapter FROM question_mgmt as q WHERE courseId='8' AND subId='16' AND ex_no!=0 AND status=1 and id!=4260 ORDER BY views desc, last_viewed_on desc limit 0,10
SELECT ex_no,question,question_no,id,chapter FROM question_mgmt as q WHERE courseId='8' AND subId='16' AND ex_no!=0 AND status=1 and id!=4260 ORDER BY last_viewed_on desc limit 0,10

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  • 4 months ago

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  • Answered by Ekta Mehta
  • 4 months ago

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  • Answered by Ekta Mehta
  • 4 months ago

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