Secondary School (English Medium) (5 to 8) इयत्ता ८ - CBSE Question Bank Solutions

Choose the incorrect statement from the following.

Forest fires are usually due to

When the clothes of a person catch ______ the person is covered with a ______ to extinguish fire. 

Some words (underlined) in the following sentence is jumbled up. Write them in their correct form.

Chittsmack does not burn by itself. 

State whether the following statement is True or False.

Carbon dioxide is an excellent fire extinguisher.

Write True/False against the following statement and also correct the false statement.

Water is the best extinguisher for fires involving electrical equipment.

Manu was heating oil to fry potato chips. The cooking oil all of a sudden caught fire, he poured water to extinguish the fire. Do you think, this action was suitable? If yes, why? If not, why not? In such a condition what should Manu have done?

What are the three essential requirements to produce fire? How fire extinguisher is useful for controlling the fire?

State whether the following statement is True or False. Correct the false statement.

Deforestation leads to an increase in the water holding capacity of the soil.

Can a forest regenerate naturally in a short period of time?

Is deforestation associated with global warming? Explain.

How does deforestation lead to frequent floods and droughts?

In the following figure, two boys A and B are shown applying force on a block. If the block moves towards the right, which one of the following statements is correct?

Whenever the surfaces in contact tend to move or move with respect to each other, the force of friction comes into play

In the following figure, a boy is shown pushing the box from right to left. The force of friction will act on the box

To sharpen the blade of a knife by rubbing it against a surface, which of the following will be most suitable?

A boy rolls a rubber ball on a wooden surface. The ball travels a short distance before coming to rest. To make the same ball travel longer distance before coming to rest, he may

The handle of a cricket bat or a badminton racquet is usually rough. Explain the reason.

When the cutting edge of a knife is put against a fast rotating stone to sharpen it, sparks are seen to fly. Explain the reason.

We have two identical metal sheets. One of them is rubbed with sand paper and the other with ordinary paper. The one rubbed with sand paper shines more than the other. Give reason.

Suppose a stick is struck against a frying pan in vacuum. Will the frying pan vibrate? Will we be able to hear the sound? Explain.