Saturday, September 16, 2017

CBSE Class 8 - Science - Half Yearly Sample Question Paper (2017-18) (#cbsePapers)


CBSE Class 8 - Science - Half Yearly Sample Question Paper (2017-18) (#cbsePapers)

TIME-3 hrs                                                                                                    MM-80 Marks

1. All questions are compulsory.
2. This paper contains 4 sections: namely SECTION A- Physics, SECTION B-Chemistry,
3. Please attempt the questions in serial order.


Q1. Fill in the blanks                                        (1x7= 7)
a) If light bends towards the normal as it goes from media A to medium B, then medium A is optically ______ than medium B.

b) For a normal eye, the ________ point is infinity.

c) A ______ is an instrument used in submarines to view objects on the surface of the sea.

d) The ______ constellation forms the shape of a hunter.

e) ______ was the first satellite sent up from the earth.

f) The galaxy we live in is called the __________.

g) ______ is the distance between the optical centre and the focus of a lens.

Q2. Give Reason :                                                      (2x2=4)
a) Will a spectrum be formed if blue light falls on a prism?
b) Why are nights so cold Mercury?

Q3. Differentiate the following:                                  (2x2=4marks)
a) Myopia and Hyermetropia
b) Opaque Body and Transparent Body

Q4.  a. State three uses of plane mirror?
     b. Give five ways  in which artificial satellites are useful to us. (3x2=6marks)

Q5. Answer in detail                                                                                            
a)  State the laws of reflection along with a suitable diagram.       (4x1=4)


Q6. Give one word:                                                 (1x5=5marks)

1. All _______ fuels are derived from organic matter.
2. Excess of CO2 in the air leads to __________ effect.
3. Burning of a piece of paper is an example of _________ combustion.
4. A substance catches fire on its own, it is called ________.
5. The best and the most important variety of coal as a fuel is _______.

Q7. Define the following:                                              (3x1=3)
a. Fractional Distillation      
b. Incomplete Combustion              
c. Calorific Value

Q8. Give Reason (2x2= 4marks)
a. When a candle is lighted, why does the wick not burn?
b. Why is coal called a fossil fuel?

Q9. Answer in brief                                                  (2x1= 2marks)
1. How does carbon dioxide help in extinguishing a fire?

Q10.  Draw a well labelled and neat diagram of candle flame and its zones.   (3marks)

Q11. Answer in detail                                                (4x2=8 marks)
a. Where are petroleum and natural gas deposits found? How is crude oil pumped out?
b. Name the four conditions necessary for combustion to take place.


Q12. Very short answer questions: -                                (1x5=5marks)
a. The process of loosening and turning soil is called _________.

b. Nitrogen fixing bacteria found in the roots of legumes are called _____________.

c. Rearing, breeding and feeding of domestic animals for commercial purpose is called _______.

d. Curd making bacteria is called as ________.

e. Microbes that sit on border line of living and non-living are called _______.

Q13. Define the following-                                (2x1=2)
a. Endemic species        
b. Biodiversity

Q14. Differentiate the following                             (2x3=6marks)
1. Deforestation vs Afforestation
2. Manure and Fertilizer
3. Nitrification and Denitrification

Q 15. a) Draw the diagram for each of the following:                  (3x3=9marks)
1. Paramecium
2. Spirogyra
3. Pencillium

b. How does salt prevent food spoilage?

c. Explain with an example howa food chain is affected when an animal becomes extinct.

Q16. Answer in detail---------------                               (4x2=8marks)
a. What precautions must be kept in mind while sowing seeds in a field?
b. Discuss fvarious ways in which communicable diseases spread from person to person.

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