Question 4 :
Paheli: When we speak, do we also vibrate any part of our body?

Question 5 :
The lower the frequency of vibration, the higher is the pitch. Is the given statement correct ?

Question 6 :
If the amplitude of vibration is large, sound is feeble. State true or false.

Question 7 :
State True or False: Noise pollution may cause partial hearing impairment.

Question 8 :
Fill in the blank: Loudness is determined by the ______ of vibration.

Question 9 :
State True or False: The lower the frequency of vibration, the higher is the pitch.

Question 11 :
A list of mediums is given. (i) wood (ii) water (iii) air (iv) vacuum. In which of these mediums can sound travel?

Question 16 :
Loudness of sound is proportional to the square of the amplitude of the vibration producing the sound. State true or false.

Question 18 :
The shape of the outer part of the ear is like a _____.

Question 23 :
<img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b1d0abf59b460d7261f333.jpeg' /> In the above figure an alarm bell is kept inside a vessel. A person standing close to it can distinctly hear the sound of alarm. Now if the air inside the vessel is removed completely how will the loudness of alarm get affected for the same person?

Question 25 :
For human ears, the audible range is 20 Hz to 20,000 Hz. State true or false.