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SUMMATIVE ASSESSMENT SKT-01

SCIENCE

Time : 2 hour 45 minutes CLASS-VIII M.M.: 80

General Instructions :

1. Marks for each type of question are indicated against it.

2. Attempt all questions in proper sequence.

3. Diagrams should be drawn neatly.

1. Answer the following questions briefly :

(a) How does atmospheric pressure vary with altitude ?

(b) Why are some fibres called synthetic ?

(c) How is Wildlife sanctuary different from national park ?

(d) Jia notes down some features of organism X.

Organism X

It is a micro-organism

It needs air, food and water

It can be used to make bread

Identify the organism

(lxl6=16)

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(2 )

(e) Does pure water conduct electricity? What can you do to increase its conductivity?

(f) What is composition of poly-wool ?

(g) The diagram below shows two types of organisms

Write one feature which is common in these organisms ?

(h) Why rayon is called artificial silk ?

(i) What are the long-term effects of using fertilizers in the field ?

(j) Two friends A and Bare applying a force of2N and 4N on a box in the same direction.

Calculate the total force applied by them.

(k) Why gold is used in pure zari work on saris and other dress materials ?

(l) Name two contact forces.

(m) What is vibration ?

(n) Name one metal which satisfies each of the following description.

I. a metal that replaces silver from silver nitrate solution

II. a metal that burns in oxygen with a· bright white light.

(o) What is the significance of Red Data Book ?

(p) Write the full form of LED.

2. How does deforestation lead to desertification ? (2xl3=26)

3. ·Saloni took a piece of burning charcoal and collected the gas evolved in a test tube :

(a) How will she find the nature of the gas ?

· (b) Write down the word equation of all the reactions taking place in this process.

- 4. Recycling of paper conserve our natural resources. How ?

5. Rahul and Rohan brought some iron nails for their class project in advance. While Rahul



(3 )

kept his iron nails neatly packed in an air tight box, Rohan carelessly left his iron nails in the

open. In which condition did they find their iron nails after some time. Give appropriate

reason for your answer.

6. A pendulum oscillates 40 times in 4 seconds. Find its time period and frequency.

7. What points should be kept in mind while sowing seeds ?

8. What is the best time to remove weeds from the field ? Why ?

9. One day Radha went to a jewelers shop with her mother. Her mother gave an old jewelry to

the goldsmith to polish. Next day when they brought the jewelry back, they found that there

was a slight loss in its weight. Explain the reason behind this.

10. Why is it dangerous to leave plastic bags near a burning stove ?

11. Describe how are we able to hear sound.

12. (i) Can we hear sound on moon ? Give reason in support of your answer.

(ii) What is the range of audible sound ?

13. You must have heard the slogan, "Say no to poly bag". Give two reasons in support of this

slogan.

14. Differentiate between

(a) monomer and polymer

(b) thermosetting plastics and thermoplastics



(4 )

15. Comment on the following statements :

(a) Refrigerators and freezers have a plastic foam core.

(b) Electrical wires have a plastic covering.

(c) Non-stick cookware have Teflon coating.

(8x3=24)

16. How does the percentage of nitrogen remains constant in atmosphere ? Explain with the

help of flowchart.

17. What happens when

(a) an iron knife is kept dipped in blue copper sulphate solution.

(b) Zinc piece is added into aluminum nitrate solution ?

(c) Silver is added into silver nitrate solution ?

18. Give reasons :

(i) Porters place a round piece of cloth on their head to lift load.

(ii) Mountaineers suffer nose bleeding at high altitudes.

(iii) Soles of shoes are grooved.

19. What is the impact of deforestation on :

(i) wildlife (ii) future generation

(iii) villages

20. (i) Suppose your writing table has titled a little. A book kept on it starts sliding down. Show

diagrammatically direction of frictional force acting on it.

(ii) Why friction is regarded as a friend and a foe ?

21., Why is water important for crops ?

22. Give reasons :

(a) Why can't copper displace zinc from its salt solution ?

(b) Why can't wires of coal drawn ?

(c) What happens when a burning matchstick is brought near to the mouth of a test tube in

which a metal has reacted with hydrochloric acid ?



23. Differentiate between

(i) sliding and static friction.

(ii) contact and non-contact force.

(2+2=4)

24. (a) Mosquitoes are harmful insects that spread diseases to man. The best way to get rid of

them is t:o get rid of any stagnant water. {1+2+2=5)

. ... · .. .... ·...· ...• .

-. .. ..,

Based on the diagram above, explain how getting rid of stagnant water prevents mosquitoes

from breeding.

(b) What steps should be taken to prevent food poisoning ?

(c) Complete the table given below :

Name of the food item

Preservative used Reason

Meat/fish -------------------r------------------

Milk 25. (i) What is electroplating ? •

(ii) With the help of a circuit diagram explain electroplating of a steel spoon. (1+4=5)

( 4 )



SUMMATIVE ASSESSMENT-I

SCIENCE

Time allowed : 15 Mins. CLASS-VIII M.M. : 10

General Instructions :

1. This question paper contains 10 questions. Each question carries 1 mark.

2. Put tick against the correct option.

1. Which of the following questions about micro-organisms are correct ?

(a) yeast is used to make bread fluffy.

(b) cultured milk contains yeast which helps in digestion.

(c) some algae help to tum milk into cheese.

(d) all micro-organisms are harmful to people.

2. Speed of sound is maximum in

(a) air

(c) liquids

(b) solids

(d) vacuum

3. When a copper vessel is exposed to moist air for long, it acquires a dull green colour

coating. The green material is a mixture of copper hydroxide Cu{OH)2 and :

(a) CuCO3 (b) CuO

(c) CuC02 (d) CuS04

4. Which of the following is a Rabi crop ?

(a) Jowar

(b) Wheat •

(c) Maize

(d) Sugarcane

P.T.O.



5. A good conductor of electricity

(a) sulphur

(b) graphite

(c) nitrogen

(d) iodine

6. Metal that is liquid at room temperature

(a) gold

(b) mercury

(c) silver

(d) sodium

7. When a ball rolls over the surface of another body, the friction is called

(a) rolling friction

(b) sliding friction

(c) static friction

(d) air drag

8. Which one of these is not a nature of plastic ?

(a) light

(b) durable

(c) strong

(d) heavy

9. The S.J. unit of frequency is

(a) newton

(b) hertz

(c) pascal

(d) second

10. A species is a group of

(a) similar animals capable of breeding with each other.

(b) similar plants capable of breeding with each other.

(c) group of different plants and animals living together. ' &

(d) similar organisms capable of breeding with each other.



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