Question

IV. True or False
State whether the given statements are true or false.
1. All human beings can hear sounds of frequencies upto 60,000 Hz.
2. The sound in a sitar is produced by plucking its strings.
3. Sound cannot travel through vacuum.
4. Sound does not need a medium for its propagation.
5. The loudness is expressed in a unit called decibel.
6. Loud sounds have high frequencies.
7. Sound travel faster in air, slower in iron.
8. Light travels much faster than sound.
9. Man cannot hear sound of bats.
10. The time taken to complete one oscillation is called frequency.
11. Shriller sound has more frequency.
12. Tabla is a musical instrument.
13. The sound could not travel in solid.
14. The pitch of a sound depends in the frequency of the waves.

Answer 1

Explanation:

1 true

2 true

3 true

4 false

5 true

6 true

7 false

8 true

9 false

10 false

11 true

12 true

13 false

14 true

Answer 2

Explanation:

Objective

This topic gives an overview of;

Sound

Sound Produced by a Vibrating Body

Sound Produced by Humans

Sound Needs a Medium for Propagation

Sound through our Ears

Sound

How do you come to know that a 'period' is over in your school? You come to know easily that someone is at your door when he knocksor you hear the sound of the doorbell. Most of the time you can make out that someone is approaching you by just hearing the foot steps.

You might have played a game called hide and seek. In this game a person is blind-folded and has to catch the remaining players. How is the blindfolded person able to guess which player is closest to her?

Sound plays an important role in our life. It helps us to communicate with one another. We hear a variety of sounds in our surroundings.

Make a list of sounds you hear in your surroundings. In the music room of your school you hear the sounds made by musical instruments like flute, tabla, harmonium etc