MCQ Questions for Class 8 Science: Ch 6 Combustion and Flame
1. Fuel may be
(a) Solid only
(b) Solid,Liquid or gas
(c) Liquid only
(d) Gas only
► (b) Solid,Liquid or gas
2. Which of the following has the characteristics of a good fuel?
(a) Coke
(b) Butane
(c) Coal
(d) Kerosene
► (b) Butane
3. Combustion is a _____ chemical reaction:
(a) volatile
(b) exothermic
(c) endothermic
(d) none of the above
► (b) exothermic
4. The substances which give heat and light after combustion are called
(a) flame
(b) fuel
(c) combustion
(d) none of these
► (b) fuel
5. Cutting trees at large scale leads to :
(a) deforestation
(b) afforestation
(c) reforestation
(d) both deforestation & afforestation
► (a) deforestation
6. What kind of reaction is combustion?
(a) Reduction
(b) Redox
(c) Substitution
(d) Oxidation
► (d) Oxidation
7. Substance that burns in oxygen to produce heat and light is called :
(a) renewable
(b) non combustible
(c) combustible
(d) limitless
► (c) combustible
8. If a glass plate/slide is held into the luminous part of candle flame we see a circular blackish ring that represents:
(a) unburnt carbon particles
(b) formation of coal
(c) burnt carbon particles
(d) Both burnt carbon particles & formation of coal
► (a) unburnt carbon particles
9. Burning of LPG is an example of :
(a) slow combustion
(b) spontaneous combustion
(c) Both slow combustion & spontaneous combustion
(d) rapid combustion
► (d) rapid combustion
10. SI unit of the calorific value of a fuel is :-
(a) KJ/kg
(b) KW/kg
(c) N/kg
(d) KJ/g
► (a) KJ/kg
11. Burning of charcoal in a closed room will produce
(a) carbon dioxide
(b) nitrogen dioxide
(c) carbon monoxide
(d) all of these
► (c) carbon monoxide
12. Which of the following is an example of rapid combustion?
(a) Candle
(b) Cracker
(c) White phosphorus
(d) Sulphur
► (a) Candle
13. The gas which supports combustion of coal is :
(a) carbon dioxide
(b) oxygen
(c) nitrogen
(d) hydrogen
► (b) oxygen
14. Amount of heat energy produced on complete combustion of 1kg of fuel is called :
(a) energy value
(b) combustion value
(c) heat value
(d) calorific value
► (d) calorific value
15. Combustion is a
(a) chemical process
(b) physical process
(c) both of these processes
(d) none of these processes
► (a) chemical process
16. A material that burns is one that can combine quickly with :
(a) hydrogen
(b) oxygen
(c) carbon
(d) water
► (b) oxygen
17. Water works as a fire extinguisher by removing :-
(a) source of combustible substance
(b) heat
(c) oxygen
(d) both oxygen & heat
► (d) both oxygen & heat
18. What is the lowest temperature at which a substance starts burning called?
(a) Minimum temperature
(b) Maximum temperature
(c) Boiling temperature
(d) Ignition temperature
► (d) Ignition temperature
19. It is dangerous to extinguish fire caused by an electric short circuit with the use of :
(a) sand
(b) carbon dioxide
(c) water
(d) carbon monoxide
► (c) water
20. Substance that does not burn in air is :
(a) sand
(b) kerosene
(c) wood
(d) diesel
► (a) sand
21. No external heat is required to start :
(a) simultaneous combustion
(b) spontaneous combustion
(c) splendid combustion
(d) spreading fire combustion
► (b) spontaneous combustion
22. CNG and LPG are the examples of
(a) solid fuels
(b) liquid fuels
(c) gaseous fuels
(d) they are not fuels
► (c) gaseous fuels
23. Which of the following is a non- combustible substance?
(a) Coke
(b) Diamond
(c) Coal
(d) Wood
► (b) Diamond
24. The products of combustion are
(a) carbon dioxide and water
(b) oxygen and water
(c) only carbon dioxide
(d) only oxygen
► (a) carbon dioxide and water