#### 3rd Term SA Mock Test 2019

7th Standard

Reg.No. :
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Science

Time : 02:15:00 Hrs
Total Marks : 60

10 x 1 = 10
1. Forest is an area with high density of __________

(a)

trees

(b)

grass

2. _______ is an example of a natural ecosystem.

(a)

(b)

Desert

3. Water exists in abundance on the planet _______

(a)

Earth

(b)

Mars

4. _______ are a huge store of water.

(a)

Oceans

(b)

Ponds

5. How much surface of the earth is covered with water?

(a)

80%

(b)

70%

(c)

60%

(d)

65%

6. Substances that catch fire easily are

(a)

inflammable

(b)

non-combustible

(c)

heavy

(d)

light

7. L.P.G is a mixture of

(a)

methane and propane

(b)

propane and butane

(c)

butane and methane

(d)

none of these

8. On the Fahrenheit scale the number of divisions between the upper and lower fixed points is

(a)

212

(b)

180

(c)

100

(d)

32

9. Ajay stands 1 m in front of a mirror. He moves 50 cm forward towards the mirror. The distance between Ajay and his image is

(a)

50cm

(b)

2 m

(c)

3 m

(d)

1 m

10. The sun gives us ----------- of heat energy per second.

(a)

1 joule

(b)

3.8$\times$1026 joule

(c)

100 joule

(d)

2.6$\times$1038 joule

11. II. Fill in the blanks

5 x 1 = 5
12. The flow of energy is always in-------------

()

one direction

13. The living components are------- and-------------

()

plants, animals

14. The lowest temperature at which fuel catches fire is called ________ (body temperature / ignition temperature)

()

ignition temperature

15. On a thermometric scale, the boiling point of water is taken as the _______ (upper fixed point / lower fixed point)

()

upper fixed point

16. White light is composed of colours-------------

()

seven

17. III. Answer any 10 in the following

10 x 2 = 20
18. Define Combustion.

19. Discuss the effects of deforestation on the following:
a) Wild animals
b) Environment

20. Match the following types of forests with their unique characteristic features.
Rain forest, Savannah, Desert, Grassland, Taiga, Tundra.

 S.No. Characteristic feature Types of Forest 1. Frequent forest fire 2. Windy weather 3. Snow and ice 4. Hot days and cold nights 5. Ice covered frozen soil 6. Plentiful rainfall
21. Write the about importance of forests?

22. Give reasons.
Kerosene burns more readily than wood.

23. Compare the characteristics of the following fuels and choose the best fuel on the basis of the responses to the following questions.
i) Coal ii) Kerosene iii) LPG
How much heat energy does it give out?

24. Compare the characteristics of the following fuels and choose the best fuel on the basis of the responses to the following questions.
i) Coal ii) Kerosene iii) LPG
Is it easy and safe to store and transport?

25. Suggest a reason for the following:
A shooting star is visible as it streaks across the night sky.

26. Suggest a reason for the following:
We cannot use an ordinary laboratory thermometer to measure the temperature of a liquid which is at 400o c.

27. Observe the pictures given above. One of them is correct and the other is wrong. Explain why the picture is wrong.

28. Differentiate between real and virtual image

29. IV. Answer any 5in detail :

5 x 5 = 25
30. Why is supply of water essential to humans?

31. a) Why has urbanisation occurred? List the ways in which urbanisation
i) benefits human
ii) harmful to wild life.
b) Suggest one way in which the effects of urbanisation can be reduced.

32. Write the three states of water and explain

33. Write a detail account on the Minjur desalination plant

34. Compare the characteristics of the following fuels and choose the best fuel on the basis of the responses to the following questions.
i) Coal ii) Kerosene iii) LPG
Does it cause pollution?

35. Describe the various zones of a candle flame.