INDIAN SCHOOL AL WADI AL KABIR

DEPARTMENT OF SCIENCE 2017-18

WS NO: 11 DATE: 07-10 2017

CLASS: VIII SOUND NAME:

I. BASIC CONCEPTS LEVEL QUESTIONS:

1. Name the quantity whose unit is hertz.

2. In which medium does the sound travel fastest: air, water or wood?

3. Name the three characteristics of sound waves.

4. Why can’t we hear the noises made by a bat?

5. How is pitch of a sound related to its frequency?

6. What is the scientific term used to denote the number of vibrations made per second.

7. Do sound waves require a medium for their propagation?

8. Name the three classes of musical instruments with examples

9.What is the function of larynx?

10.What is an echo?

11. Which of the following has a high pitch?

12.How noise is different from a music?

II. INTERMEDIATE LEVEL QUESTIONS:

1.  Distinguish between the following.

a.  Audible and inaudible sound

b.  Loudness and pitch.

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2.  Why are thick curtains and false ceilings used in large theatre halls?

3.  If you want sound of low pitch, what characteristic of sound, do you have to change?

4.  What is time period of a simple pendulum?

5.  Give any four causes of noise pollution.

6.  Name one musical instrument each in which the sound is produced:

a.  By vibrating a stretched string.

b.  By vibrating a stretched membrane.

c.  By vibrating air enclosed in a tube.

7.  Mention any two factors which can affect the speed of a sound.

8.  When we put our ear to a railway line, we can hear the sound of an approaching train even when the train is far off but its sound cannot be heard through the air. Why?

9.  Suggest any four measures to control noise pollution.

10.  Expand SONAR. State the working principle and applications of SONAR.

11.  Complete the flowchart showing the working of a human ear

12.  How can you increase the pitch of a stringed instrument?

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III. ADVANCED LEVEL QUESTIONS :

1.  Eardrum shattering explosions occur in the sun but we don’t hear it. Why?

2.  How do trees planted along road side help in the reduction of noise pollution?

3.  Why do our footsteps produce loud sound while walking on a marble floor as compared to walking on a carpet?

4.  Label the parts marked in the given diagram.

5.  There was a party at Aman’s house. Loud music was being played at night. His neighbor came and requested him to lower the sound of the music system as his grandfather was not well and was resting. Aman lowered the volume of the music system at once.

a.  Do you think Aman did the right thing? Why or why not?

b.  What value do you learn from Aman?

c.  If you were at Aman’s place, would you have done the same thing?

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