Answer the following questions:[3 M]

Question 13 Marks

Explain why it is not safe to go out with an umbrella when there is heavy raine lightning or thunder.

Answer

Large amount of charges get built up in the clouds in rainy and stormy weather.

Sometimes these charges are transferred to the earth in the form of a bolt of lightning.
Wire of umbrella is made up of metal and cloth is made up of synthetic material.
If lightning strikes, then umbrella catches it and there are chances of fire and it would be dangerous.
So it is not safe to go out with an umbrella when there is heavy rain.

Question 23 Marks

Why is lightning not seen every day during the rainy season?

Answer

When air and clouds rub against each other in the sky the upper part of some clouds becomes positively charged and the lower side become negatively charged.
When this negative charge at the bottom of the cloud becomes much larger than the charge on the ground, it starts flowing towards the ground in stages, but this doesn’t happen every day. So lightning is not seen every day during the rainy season.

Question 33 Marks

Why do farmers stick an iron staff into the ground while working in the field in rainy conditions?

Answer

Large amount of charges get built up in the clouds in rainy and stormy weather.
Sometimes these charges are transferred to the earth in the form of a bolt of lightning.
Due to iron staff, the charges will be conducted to the earth through iron metal and spread quickly into the ground.
This way farmers are saved from lighting strike.

Question 43 Marks

In the lightning conductor, what provision is made for spreading the electricity into the ground?

Answer

The lightning conductor, consists of a long i copper strip with one end forked. This end is ‘ at the highest part of the building.
The other end of the strip is connected to a plate of cast iron.
A pit is dug in the ground, coal and salt are filled into the pit and the iron plate is placed upright in the pit.
There is also a provision for pouring water into it.
This helps to spread the electric charge quickly into the ground.

Question 53 Marks

How are charges generated?

Answer

Friction causes a charge to develop, because on rubbing, some negative particles are transferred from one substance to the other and the later develops a negative charge.
The substance from which particles are removed lose negative charge and hence, it develops a positive charge.

Question 63 Marks

How will you protect yourself from lightning?

Answer

To protect from the lightning, we have to put lightning conductor on high rise buildings,
we should not stand under a tree in rainy and stormy weather.
We should not go out with an umbrella in heavy rain, lightning or thunder.

Science Answer the following questions:[3 M]