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

A ball of dough is rolled into a flat chapatti. Name the force exerted to change the shape of the dough.

A girl is pushing a box towards east direction. In which direction should her friend push the box so that it moves faster in the same direction?

Two women are of the same weight. One wears sandals with pointed heels while the other wears sandals with flat soles. Which one would feel more comfortable while walking on a sandy beach? Give reasons for your answer.

Electric current is to be passed from one body to another. For this purpose, the two bodies must be joined by 

During the construction of a building, the lightning conductor was left hanging in the air by mistake. Would the lightning conductor be still effective? Explain.

If air and cloud were good conductors of electricity, do you think lightning could occur? Explain.

Identify the lightning conductor and the copper plate in the following figure.

If the materials used for constructing a building were good conductors, do you think lightning will strike the building. Will the lightning conductor be still required to be installed in the building?

You might have observed on a dry day that when you touch the screen of a television or computer monitor (with picture tube), you get a slight shock. Why does it happen?

Explain how does lightning conductor protects a building from getting struck by lightning.

Explain how lightning takes place.

Explain why it is safer to use a wireless telephone instead of a landline telephone during lightning.

What precautions would you take if lightning occurs while you are outside the house?

Plastics are flexible and waterproof and some are even UV resistant.

Suppose you are outside your home and an earthquake strikes. What precaution would you take to protect yourself?

List three states in India where earthquakes are more likely to strike.

Earthquakes can be predicted in advance.

Name the scale on which the destructive energy of an earthquake is measured. An earthquake measures 3 on this scale. Would it be recorded by a seismograph? Is it likely to cause much damage?

Assertion and Reason

A: It takes a very long time for nylon clothes to breakdown into microfibers but cotton clothes need only six months to decompose.

R: Nylon made out of petrochemicals is non-biodegradable and cotton cloth is biodegradable.

Which of the following is not a common property of plastics?