Question 1 :
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 4 :
Does the voice of a woman has a higher frequency than that of a man ?

Question 5 :
Fill in the blank: Loudness is determined by the ______ of vibration.

Question 6 :
State True or False: The number of oscillations per second of a vibrating object is called its time period.

Question 7 :
State True or False: The lower the frequency of vibration, the higher is the pitch.

Question 9 :
A pendulum oscillates 40 times in 4 seconds. Find its frequency.

Question 10 :
The to and fro motion of an object is known as _______ motion.

Question 11 :
State True or False: Noise pollution may cause partial hearing impairment.

Question 12 :
Fill in the blank: Shrillness of a sound is determined by the _____ of vibration.

Question 13 :
The shape of the outer part of the ear is like a _____.

Question 14 :
Does the frequency of the voice of a child is higher than that of an adult?

Question 15 :
<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 16 :
A pendulum oscillates 40 times in 4 seconds. Find its frequency.

Question 19 :
The shrillness of a sound is determined by the __________ of vibration.

Question 20 :
Your parents are going to buy a house. They have been offered one on the roadside and another three lanes away from the roadside. Which house would you suggest your parents should buy?

Question 21 :
An object is vibrating at 50 hertz. What is its time period?

Question 24 :
Suppose a stick is struck against a frying pan in vacuum. Will we be able to hear the sound?