class 8 sound worksheet

Lesson 13- Sound

 I. Fill in the blanks. 
1. To and fro or back and forth motion of an object is called ___________. 
2. In humans the sound is produced by the ________ or the ___________. 
3. ________ are stretched across the voice box or larynx. 
4. The vocal cords in men are about ______ mm long. 
5. Noise becomes physically painful at _____ dB. 
6. Frequency determines the ________ of a sound. 
7. ________ on the roadside and elsewhere can reduce noise pollution. 
8. _________ and _______ are two important properties of sound. 9. ________ senses the vibrations of sound. 

10. Time taken by an object to complete one oscillation is called _______________.

11. Loudness is determined by the _______________________of vibration.

12. The unit of frequency is ________________________.

13. Unwanted sound is called ______________________.

14. Shrillness of a sound is determined by the __________________________.

15. The number of oscillation in one second is called ____________________.

16. The hearing range of human ear is _____________

17. Sound cannot travel in __________________.

18. Sound can travel in _____________________.

19. The pitch of sound depends on __________________.

II. Name the following 
1. An instrument used for investigating and tracking many medical problems. 
2. Name the major causes of noise pollution. 
3. Name the sources in home which may lead to noise. 
4. Give examples of objects which produce sounds of low frequency or low pitched.
 5. Give examples of objects which produce sound of high frequency or high pitched.

III.choose the correct answer :

1. Ear drum is a part of ____________________ [ sound producing organ or hearing organ]

2. The voice box is also called _________________ [ Larynx / mouth]

3. Large amplitude of sound vibrations will produce __________________________ [ Loud sound / slow sound]

4. Voice of which of following is likely to have minimum frequency _____________________________ [ Baby girl / A woman]

5. The unit of loudness is ________________ ( decibel / Hertz)

IV.Answer the following :

1. Name the sound producing organ in human.

2. How does sound travel from one place to another ?

3. How is sound produced ?

4. What do you mean by musical sound ?

5. How does the amplitude affect the loudness of vibration? 
6. The sound from a mosquito is produced when it vibrates its wing at an average rate of 500 vibrations per second. What is its time period?