Question 1 :
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 2 :
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 3 :
Does the frequency of the voice of a child is higher than that of an adult?
Question 4 :
Time taken by an object to complete one oscillation is called __________.
Question 5 :
Presence of excessive noise in the surroundings may cause many health related problems. True or false ?
Question 7 :
In order to reduce the loudness of a sound we have to
Question 9 :
State True or False: The number of oscillations per second of a vibrating object is called its time period.
Question 11 :
Suppose a stick is struck against a frying pan in vacuum. Will we be able to hear the sound?
Question 14 :
Lack of sleep, hypertension, anxiety and many more health disorders may be caused by ______________
Question 16 :
For human ear, the range of audible frequencies is roughly from _____ to _____ Hz.
Question 17 :
State true or false. A whistle has a high frequency and therefore, produces a sound of low pitch
Question 18 :
Noise pollution may cause partial hearing impairment. Is that correct ?
Question 19 :
How can we recognize many familiar sounds without seeing the objects producing them?
Question 23 :
Loudness of sound is proportional to the square of the amplitude of the vibration producing the sound. State true or false.
Question 26 :
Lightning and thunder take place in the sky at the same and at the same distance from us. Lightning is seen earlier and thunder is heard later. Can you explain why?
Question 27 :
Boojho saw a cracker burst at night at a distance from his house. He heard the sound of the cracker a little later after seeing the cracker burst. Give reason for the delay in hearing the sound.
Question 28 :
State True or False: Unwanted or unpleasant sound is termed as music.
Question 33 :
The to and fro motion of an object is known as _______ motion.
Question 34 :
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 36 :
The shape of the outer part of the ear is like a _____.
Question 37 :
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 40 :
Which part of our body vibrate when we hear a sound?
Question 41 :
Does the voice of a woman has a higher frequency than that of a man ?
Question 42 : <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 43 :
State True or False: Noise pollution may cause partial hearing impairment.
Question 44 :
We have a stringed musical instrument. The string is plucked in the middle first with a force of greater magnitude and then with a force of smaller magnitude. In which case would the instrument produce a louder sound?
Question 45 :
For human ears, the audible range is 20 Hz to 20,000 Hz. State true or false.
Question 46 :
The number of oscillations per second of a vibrating object is called its time period. True or false ?
Question 47 :
When we hear a sound, does any part of our body vibrate?
Question 49 :
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?
