Question 3 :
When we strike the membrane of a 'mridangam', we hear some sound. It's the sound of

Question 5 :
The townhall building is situated close to Boojho’s house. There is a clock on the top of the townhall building which rings the bell every hour. Boojho has noticed that the sound of the clock appears to be much clearer at night. Explain.

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

Question 7 :
Presence of excessive noise in the surroundings may cause many health related problems. True or false ?

Question 8 :
A pendulum oscillates 40 times in 4 seconds. Find its frequency.

Question 10 :
<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 11 :
A pendulum oscillates 40 times in 4 seconds. Find its time period.

Question 14 :
An object is vibrating at 50 hertz. What is its time period?

Question 15 :
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 19 :
The sound from a mosquito is produced when it vibrates its wings at an average rate of 500 vibrations per second. What is the time period of the vibration?

Question 20 :
Which of the following statements are correct? (i) Sound is produced by vibrations. (ii) Sound requires a medium for propagation. (iii) Light and sound both require a medium for propagation. (iv) Sound travels slower than light.