CBSE Class 8 Science Science and Technology Assignment Set A

Section – A : Physics

1) Draw a ray- diagram of periscope. Write its working principle.

2) Describe the phases of moon with the help of diagram.

3) Differentiate between :

i) stars and planets ii) planets and satellite

4) What are the common eye defects? Give their causes and corrective measures.

5) Draw a well labelled diagram of the human eye.

6) What is a virtual image? Why is the image formed by a plane mirror a virtual image ?

7) What is meant by diffused reflection? How is diffused reflection useful for us?

8) The global climate has always fluctuated. Millions of years ago ,some parts of the world that are now quite warm , were covered with ice and over recent centuries, average temperature have risen and fallen in cycles. What is new, however is that current and future climate change will be caused not just by natural events but also by activities of human beings.

Suggests three simple ways to help save the climate of our planet.

Section – B : Chemistry

1) Define:

i) combustion ii) Ignition temperature iii) Flame

iv) Fuel v) Calorific value

2) What will you use to put off fire caused by electrical gadgets? Give reason.

3) List the harmful effects of burning carbon containing fuels.

4) Why does a log of wood not burn by a matchstick but a paper does?

5) What is greenhouse effect? What are the consequences of greenhouse effect?

6) What is acid rain? Write a balanced chemical equation representing formation of H₂SO₄ in the atmosphere.

7) Value Based Question :

Akash has two different types of fuel one is kerosene and other is LPG, which fuel will he use and why? What is the values associated behind it

Section – C : Biology

1. Name any three major causes for loss of biodiversity.

2. What is migration? Name two migratory animal and their cause of migration.

3. What are agricultural implements? Name any three and mention its use.

4. Define irrigation. Compare traditional and modern methods of irrigation.

5. In a school, it is recommended to all student to donate sapling on their birthday and also to gift their friends a sapling on their

a. What values does school want to inculcate in students?

b. How this act is going to help the society.

6. Mention any five importance of tilling/ploughing.

7. Define fertilization. Describe how fertilization take place inside the female body.

8. How can the sex of a child be determined with the help of chromosomes?