Question 1 :
Paheli: When we speak, do we also vibrate any part of our body?

Question 2 :
State True or False: For human ears, the audible range is 20 Hz to 20,000 Hz

Question 3 :
Suppose a stick is struck against a frying pan in vacuum. Will we be able to hear the sound?

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

Question 11 :
Which part of our body vibrate when we hear a sound?

Question 12 :
Lightning can be seen the moment it occurs. Paheli observes lightning in her area. She hears the sound 5 s after she observed lightning. How far is she from the place where lightning occurs? (speed of sound = 330 m/s).

Question 13 :
A pendulum oscillates 40 times in 4 seconds. Find its frequency.

Question 15 :
If the amplitude of vibration is large, sound is feeble. State true or false.

Question 16 :
When sound enters into ear, it travels down a canal at the end of which there is a thin stretched membrane. It is called the __________.

Question 17 :
<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 18 :
Unwanted or unpleasant sound is termed as music. True or False ?