8th Science Periodic Test I (2018-19)
Time: 3 hour
M.M. 80 marks
- The question paper comprises of two sections A and B. You have to attempt both the sections.
- All questions are compulsory. However an internal choice will be provided in three questions of three marks and two questions of five marks each and one one question (assessing the practical skills) of two marks.
- All questions of section A and B are to be attempted separately.
- Question numbers 1 to 2 in Sector A are one mark questions. These are to be answered in one word or in one sentence.
- Question numbers 3 to 5 in Section A are two mark questions. These are to be answered in 30 words each.
- Question numbers 6 to 15 in Section A are five marks questions. These are to be answered in 50 words each.
- Question number 16 to 21 in Section A are five marks questions. These are to be answered in 70 words each.
- Question numbers 22 to 27 in Section B are two mark questions based on practical skills. These are to be answered in brief.
SECTION – A
Question: 1. What do you mean by streamlined shape? Give an example you see in nature. (1 marks)
Question: 2. Draw the shape of the following cells-spherical red blood cells of humans and spindle shaped muscle cells. (1 marks)
Question: 3. Why does the loosening of soil allow roots to breath easily? (2 marks)
Question: 4. (2 marks)
- Define force.
- Two friends A and B are applying a force of 6 Newton and 4 Newton on a box in the same direction. What will be the total force applied by them?
Question: 5. (2 marks)
- What are endemic species? (2 marks)
- Name two animal species which have become extinct in the past years.
Question: 6. State any one use of each of the following: (3 marks)
- Coal gas
- Coal tar
Question: 7. (3 marks)
- Match the terms of column A correctly with the phrases given in Column B.
Column AColumn B1. Polyester(i). Prepared by using wood pulp.2. Teflon(ii).Used for making parachutes and stockings.3. Rayon(iii).Used to make non-stick cookwares.4. Nylon(iv). Fabries do not wrinkle easily.
- Name the polymer for cotton.
Question: 8. Give reasons (3 marks)
- LPG is the best domestic fuel than wood.
- Water is not used to control fire involving oil or petrol.
- When the clothes of a person catch fire, the person is covered with a blanket.
Question: 9. (3 marks)
- What do you mean by microorganism?
- How are viruses different from other microorganisms?
Question: 10. Name the scale on which the destructive energy of an earthquake is measured. An earthquake measures 8 on this scale. Would it be recorded by a seismograph? Is it likely to cause much damage? Why? (3 marks)
What is a lightening conductor? How can lightening conductor save a tall building? Explain with the help of diagram.
Question: 11. What are the advantage of using manure? Write any three points. (3 marks)
Write a short note on storage of food grains.
Question: 12. (3 mark)
- Define friction.
- Explain why sliding friction is less than static friction.
- Why it is easier to move a box which is already moving than the one which is at rest?
- Differentiate between rolling friction and sliding friction.
Question: 13. (3 marks)
- How is a wildlife sanctuary different from a national Park?
- Why should we conserve biodiversity?
Question: 14. Explain with the help of an activity that force can change the state of motion. (3 marks)
Question: 15. What is the function of the following in the cell: (3 marks)
- Cell wall
Question: 16. (5 marks)
- Name two contact forces.
- Why do we observe sparks coming out from a synthetic shirt when we take it off our body?
- Which force pulls the iron nails towards a magnet?
- State the two factors is applied opposite to the moon, What will happen to the speed of the objective?
- Define atmospheric pressure.
- What happens to the atmospheric pressure on mountains?
- Explain, why the skiers use flat board ski?
Question: 17. (5 marks)
- Draw a well labelled diagram of an animal cell.
- Different between unicellular and multi-cellular organisms. Write any two points.
- Draw a well labelled diagram of a plant cell.
- Differentiate between prokaryotic and eukaryotic cells. Write any two points.
Question: 18. (5 marks)
- “Even thought plastics are very useful, they are not environment friendly.” Justify the statement.
- Why are electric plugs, Switches or plug boards make up of thermosetting plastics.
- What is PET? How is it useful for us?
Question: 19. (5 marks)
- What steps should be taken to protect yourself inn case of an earthquake, if you are at home?
- Why does the aluminium strips in an electroscope:
(i). Diverge when touched with a charged glass rod.
(ii). Fold back when touched with hands.
(iii). Fold back when touched with a charged ebonite rod?
Question: 20. (5 marks)
- What do you mean by deforestation?
- Explain how deforestation can lead to desertification and global warming.
- What is red data book?
Question: 21. (5 marks)
- Friction is a necessary evil. Comment.
- Explain briefly two disadvantage of friction.
- How does a ball bearing reduce friction?
SECTION – B
Question: 22. (2 marks)
- Name the device used to measure the liquid pressure.
- In a bottle, if there are four holes all of them at different height. Will it affect the pressure? How?