Balbharati solutions for जनरल सायन्स इंटेगरटेड [इंग्रजी] इयत्ता ६ महाराष्ट्र राज्य मंडळ chapter 13 - Sound [Latest edition]

Some sound is depicted in the picture below. Have you heard this sound? Put a tick mark (✓) in the box if you have, and a cross (×) if you have not. What word is used in your locality to denote this sound? Write it below the picture.

Picture	Have you heard it?	Word used for the sound

Which sounds do you hear during the recess in the school?

When there is silence in the classroom, close your eyes and sit quietly. Which sounds in your surroundings can you hear now?

When a song is being played on a radio or a music system in the house, place your hand on its speaker. What do you feel?
Put off the music. What do you feel now?

Take a rubber band and stretch it as shown in the picture. Pluck the stretched band.

Spread some sawdust or mustard seeds or sand on the diaphragm of a tabla. Knock on the diaphragm lightly with a finger.

• What do you see happening so long as the tabla makes a sound? What happens when the sound stops?
• What do we understand from these observations?

The sounds of a sitar, a bell, water that drops from a tap, and a saucer that breaks on falling down – what is it that vibrates when these sounds are produced?

Take a pot filled with water. Strike it lightly on its rim.

• What do you see?
• Why are waves formed on the water in the pot?

Take two balloons. Fill air m one and water in the other. Press the balloon filled with air against your ear as shown in the picture. Rub a finger on the balloon and listen to the sound. Repeat the same activity with the balloon filled with water. 

Through which balloon do we hear a clearer sound?

Stand at the end of a big table and make a friend stand at the other end. Ask the friend to knock lightly on the table. You will hear a faint sound.

Now you press your ear to the table and ask the friend to repeat the knock. What difference do you notice?

Sound travels in the form of waves through air, water or through a solid and reaches our ears. Sound is propagated more clearly through a liquid than through air; it is heard. most clearly through a solid. Why is this so?

If a bell is hung in a vacuum container, will its sound be heard outside?

Which of these sounds is pleasant?

Which sounds are a nuisance to people?

1. Make a list of all the sounds implied in the picture.
2. How would this atmosphere affect a person who is not feeling well?
3. Would you be able to study in these conditions?

The flapping of the wings of the bee or the mosquito produces a humming sound. Have you heard such sounds?

The propagation of sound does not occur through a ______.

Noise pollution is a ______ issue.

The sound which is disagreeable to the ears is called ______.

Noise has adverse effects on our ______.

What should we do?

The silencer of a motorcycle is broken.

What should we do?

A factory in the surroundings is producing continuous loud noise.

Write the answer in your own words.

What is meant by vibration?

Write the answer in your own words.

Explain with the help of practical examples how sound is propagated through solids.

Write the answer in your own words.

What is meant by noise pollution?

Write the answer in your own words.

What measures will you take to control noise pollution?

Complete the table.

Prepare a list of the harsh sounds heard near your house. Write about those sounds which produce noise pollution.

Collect information about places where loud noise is prohibited and discuss why it is so.