Science Class X (CBSE)
Sample Paper Set - VI (Solved)

General Instructions :

(i)   All questions are compulsary.
(ii) Question number 1 to 10 are very short answer question,carrying 1 mark each.They are to be answered in one or two sentences.
(iii) Question number 11 to 20 are short answer questions,each carrying 2 marks. Answer to them should not exceed 40 words each.
(iv)  Question numbers 21 to 30 are also short answer questions,each carrying 3 marks. Answer to them should not exceed 60 words each.
(v) Question numbers 31 to 33 are long answer questions,each carrying 5 marks. Answer to them should not normally exceed 100 words each.

Q.1 Name the orbit of the satellites that help in satellite communication.
Ans1. Geostationary satellite

Q.2 A torch cell converts one form of energy into another form. Name these two forms.
Ans2. Chemical energy Electrical energy

Q.3 Name the process that forms the basis of hydrogen bomb.
Ans3. Nuclear fusion

Q.4 How does the conductivity of a semi conductor change when certain impurities are added to it ?
Ans4. Impurities increase the conductivity of the semi-conductors.

Q.5 Name any two constituents of petroleum which are not used as fuel.
Ans5. Asphalt and lubricating oil

Q.6 Why does common salt become moist in rainy season?
Ans6. Common salt contains impurities of magnesium chloride, which make it deliquescent and it absorbs water from humid air and becomes moist.

Q.7 Which property of diamond makes it a suitable material for high precision thermometers ?
Ans7. Diamond has a very high melting point which makes it a good substance to be used in high temperature thermometres.

Q.8 Name the Vitamin which gets oxidised when cut fruits are left exposed to air for a long time.
Ans8. Vitamin C

Q.9 In a food chain comprising lion, grass and deer, which will (i) transfer the maximum amount of energy (ii) receive minimum amout of energy.
Ans9. (i) Grass will transfer the maximum amount of energy.
(ii) The lion will recieve the minimum amount of energy.

Q.10 Which of the following is a true solution ?
Ans10. Vinegar in water is a true solution.


Q.11 Cadmium rods play an important role in a nuclear reactor. What happens (i) when they are completely inserted into nuclear fuel, and (ii) when they are slowly withdrawn from nuclear fuel.
Ans11. (i) When cadmium rods are completely inserted into fuel, all neutrons are absorbed and the chain reaction of the nuclear fission stops.
(ii) When these rods are slowly withdrawn the fission reaction starts and goes on increasing as the rods get withdrawn. They are withdrawn till they absorb the correct number of neutrons leaving behind just the right number of neutrons to sustain the reaction and yield energy at a constant rate.


Q.12 Mention any two differences between a planet and a star.
Ans13.

Q.20 What is immunity ? Name the diseases against which DPT vaccine acts as a preventive measure.
Ans20. Immunity is the natural defence of the body to fight infections.
DPT vaccine acts as a preventive measure for the following three diseases:
D : Diphtheria
P : Pertussis (Whooping Cough)
T : Tetanus