This quiz works best with JavaScript enabled. Home > Cbse > Class 8 > Science > Combustion And Flame > Class 8 Science Chapter 6 Combustion And Flame – Quiz 3 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 8 Science Chapter 6 Combustion And Flame Quiz 3 (60 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. The calorific value of a fuel is measured in ..... per unit mass. A) Calories per liter. B) Grams per cubic meter. C) Joules or kilojoules per kilogram. D) Watts per kilogram. Show Answer Correct Answer: C) Joules or kilojoules per kilogram. 2. Lowest temperature at which a substance catches fire is known as A) Flaming temperature. B) Ignition temperature. C) Lowest temperature. D) Burning temperature. Show Answer Correct Answer: B) Ignition temperature. 3. The amount of heat energy produced on complete combustion of 1 kg of fuel is called A) Significant value. B) Internal value. C) Calorific value. D) Heat value. Show Answer Correct Answer: C) Calorific value. 4. Rapid combustion is A) When gas burns, it produces heat & light. B) When material suddenly burst into flames. C) When there is evolution of heat. D) None of these. Show Answer Correct Answer: A) When gas burns, it produces heat & light. 5. Partial combustion takes place in which zone of a candle flame? A) Outer. B) Middle. C) Inner. D) None of the above. Show Answer Correct Answer: B) Middle. 6. While cooking, if the bottom of the vessel is getting black on the outside, it means that A) The fuel has high calorific value. B) The fuel is burning completely. C) The food is not cooked completely. D) The fuel is not burning completely. Show Answer Correct Answer: D) The fuel is not burning completely. 7. In a combustion reaction, fuel reacts with ..... A) Oxygen. B) Hydrogen. C) Carbon dioxide. D) Nitrogen. Show Answer Correct Answer: A) Oxygen. 8. There are three factors which supports burning. Fire extinguisher affects which factor? A) All given below. B) Supply of oxygen. C) Supply of combustible substance. D) Lower down the ignition temperature. Show Answer Correct Answer: B) Supply of oxygen. 9. Is water combustible? A) Yes. B) No. C) All the above. D) None of the above. Show Answer Correct Answer: B) No. 10. Which of the following oxides are present in acid rain A) Phosphorus oxides. B) Sulphur oxides. C) Nitrogen oxides. D) B and c. Show Answer Correct Answer: D) B and c. 11. The fuel with high calorific value A) Hydrogen. B) Petrol. C) LPG. D) Kerosene oil. Show Answer Correct Answer: A) Hydrogen. 12. What is the main chemical component present in striking surface of a matchbox? A) Graphite. B) Potassium. C) Phosphorus. D) Potassium chlorate. Show Answer Correct Answer: C) Phosphorus. 13. Which of the following is the maximum coal producing state in India? A) ORISSA. B) WEST BENGAL. C) JHARKHAND. D) ASSAM. Show Answer Correct Answer: C) JHARKHAND. 14. Petrol can be saved by A) Driving at a constant & moderate speed. B) Ensuring correct type pressure. C) Switching off the engine at traffic lights. D) All of these. Show Answer Correct Answer: D) All of these. 15. Which zone represent the partial (half) combustion in candle flame A) Lower zone. B) Inner zone. C) Outer zone. D) Middle zone. Show Answer Correct Answer: D) Middle zone. 16. What is the main characteristic of a luminous flame? A) A flame that produces a lot of smoke and soot. B) A flame that is completely invisible to the eye. C) A bright, glowing appearance due to incandescent particles. D) A cool, blue flame with no visible light. Show Answer Correct Answer: C) A bright, glowing appearance due to incandescent particles. 17. Burning of white phosphorus is an example of A) Spontaneous combustion. B) Rapid combustion. C) Explosive combustion. D) None of these. Show Answer Correct Answer: A) Spontaneous combustion. 18. Combustion is a reaction in which a substance reacts with A) Hydrogen. B) Oxygen. C) Chlorine. D) Nitrogen. Show Answer Correct Answer: B) Oxygen. 19. Which of the following fuel gases has the highest calorific value? A) Coal bed methane (CBM). B) Sewage gas. C) Liquefied petroleum gas (LPG). D) Natural gas. Show Answer Correct Answer: C) Liquefied petroleum gas (LPG). 20. What are the 3 types of combustion? A) Inflammable combustion, Rapid combustion, calorific combustion. B) Fuel combustion, industrial combustion, luminous combustion. C) Rapid combustion, spontaneous combustion, explosion. D) None of the above. Show Answer Correct Answer: C) Rapid combustion, spontaneous combustion, explosion. 21. Of the following inflammable substance is A) Petrol. B) Coal piece. C) Wood. D) All of these. Show Answer Correct Answer: A) Petrol. 22. The outermost zone of a candle flame is the: A) Hottest part. B) Coldest part. C) Least hot part. D) Moderately hot part. Show Answer Correct Answer: A) Hottest part. 23. What is the unit for expressing the calorific value of a fuel? A) M/sec. B) KJ/Kg. C) Kg. D) Kg/Kj. Show Answer Correct Answer: B) KJ/Kg. 24. LPG is not used as A) For making paints. B) For industries. C) For running automobile. D) Fuels for home. Show Answer Correct Answer: A) For making paints. 25. Water is used to extinguish fire because it A) Raises the ignition temperature of a burning substance. B) Conducts heat. C) Cools the burning substance to a temperature below its ignition temperature. D) Lowers the ignition temperature of the burning substance. Show Answer Correct Answer: C) Cools the burning substance to a temperature below its ignition temperature. 26. Charcoal burns in air producing A) O$_{2}$. B) CO. C) CO$_{2}$. D) H$_{2}$. Show Answer Correct Answer: C) CO$_{2}$. 27. How much is the minimum temperature that begins to burn the material on fire? A) Melt-point. B) Boiling point. C) Freezing point. D) Combustion temperature. Show Answer Correct Answer: D) Combustion temperature. 28. The least hot zone of a candle flame is A) Dark zone. B) Non-lumious zone. C) Luminous. D) Blue zone at the base of the wick. Show Answer Correct Answer: A) Dark zone. 29. Name the most common fuel used in homes. A) Kerosene. B) Petrol. C) Wax. D) Liquified Petroleum Gas. Show Answer Correct Answer: D) Liquified Petroleum Gas. 30. Which of the following is not a by-product fuel? A) Blast furnace gas. B) Refinery gas. C) Coke oven gas. D) Producer gas. Show Answer Correct Answer: D) Producer gas. 31. Incomplete combustion gives out ..... A) Soot. B) CO2. C) Water, heat and light. D) Everything given here. Show Answer Correct Answer: D) Everything given here. 32. The hottest part of a candle flame is: A) Dark inner zone. B) Blue zone. C) Visible zone. D) Invisible zone. Show Answer Correct Answer: D) Invisible zone. 33. The substance which vaporizes during burning gives ..... A) Light. B) Magnesium Oxide. C) Heat. D) Flame. Show Answer Correct Answer: D) Flame. 34. A combustible substance maybe solid, liquid or gas. A) True. B) False. C) All the above. D) None of the above. Show Answer Correct Answer: A) True. 35. Cutting off trees at large scale leads to A) Deforestation. B) Afforestation. C) Reforestation. D) Both deforestation & afforestation. Show Answer Correct Answer: A) Deforestation. 36. The substances like kerosene, oil and molten wax which vaporize during burning forms flames whereas charcoal does not vaporize, do does not produce flames. A) True. B) False. C) All the above. D) None of the above. Show Answer Correct Answer: A) True. 37. A lot of dry powder of one of the chemicals can be released over a fire to extinguish it. This chemical is: A) Baking soda. B) Washing soda. C) Bitumen. D) Plaster of Paris. Show Answer Correct Answer: A) Baking soda. 38. True or false:The burning of white phosphorus is a rapid combustion A) TRUE. B) FALSE. C) All the above. D) None of the above. Show Answer Correct Answer: B) FALSE. 39. Out of these which has lower ignition temperature A) Wood. B) Kerosene oil. C) Vegetable oil. D) Paper. Show Answer Correct Answer: B) Kerosene oil. 40. Oxides of sulphur and dissolve in rainwater and form acid rains. A) True. B) False. C) All the above. D) None of the above. Show Answer Correct Answer: A) True. 41. Write the chemical process that takes place in soda-acid fire extinguisher ..... (type the formula) A) Endhor. B) Sniff + H2SO4 $\rightarrow$ Nasso 4 + A + worse. C) NaHCO3 + H2SO4 $\rightarrow$ NaSO4. D) 2NaHCO + H2SO4 $\rightarrow$ Na2SO4 + 2H2O. Show Answer Correct Answer: A) Endhor. 42. Magnesium burns with white dazzling light. Charcol burns producing heat and light. A) First statement is true. B) Second statement is true. C) Both the statements are true. D) Both the statements are false. Show Answer Correct Answer: C) Both the statements are true. 43. CNG & LPG are examples of A) They are not fuels. B) Gaseous fuels. C) Liquid fuels. D) Solid fuels. Show Answer Correct Answer: B) Gaseous fuels. 44. Which one of the following is an inflammable substance: A) Kerosene oil. B) Paper. C) Coke. D) Wood. Show Answer Correct Answer: B) Paper. 45. Why should you not add water on burning oil? A) It makes the fire explode and spread. B) It puts the fire out too quickly. C) Water does not put out fires. D) It takes too long to put out the fire. Show Answer Correct Answer: A) It makes the fire explode and spread. 46. On a cold winter night, the persons sleeping in a room with closed door and windows with a coal fire burning inside may die due to excessive accumulation of: A) Carbon monoxide. B) Nitrogen dioxide. C) Nitrogen monoxide. D) Carbon dioxide. Show Answer Correct Answer: A) Carbon monoxide. 47. In the following what is the status of the need to occur in combustion? A) Wind. B) Metal. C) Water. D) Plastic. Show Answer Correct Answer: A) Wind. 48. Which of the following statements is incorrect about carbon dioxide acting as a fire extinguisher for electrical fires? A) It is not combustible. B) It is heavier than air. C) It does not support combustion. D) It is lighter than air. Show Answer Correct Answer: D) It is lighter than air. 49. Which of the following does not produce flame while burning A) Petrol. B) Diesel. C) Charcoal. D) Wax. Show Answer Correct Answer: C) Charcoal. 50. The substance that undergoes combustion is said to be A) FLAME. B) WAX. C) BURNING. D) COMBUSTIBLE. Show Answer Correct Answer: D) COMBUSTIBLE. 51. A blue flame indicates ..... combustion. A) Incomplete. B) Inefficient. C) Partial. D) Complete. Show Answer Correct Answer: D) Complete. 52. Bunsen burner is an example of a/an ..... burner. A) Rotary cup. B) Outside mixing/diffusion flame/nozzle mix type. C) Inside mixing/premix type. D) Submerged combustion. Show Answer Correct Answer: C) Inside mixing/premix type. 53. The lowest temperature at which a substance catches fire is called its ..... A) Combustion. B) Inflammability. C) Ignition temperature. D) None of the above. Show Answer Correct Answer: C) Ignition temperature. 54. The substance which ..... during burning give flames, A) Boils. B) Heats. C) Spray. D) Melts. Show Answer Correct Answer: C) Spray. 55. In what type of matter can a fuel exist A) Solid. B) Liquid. C) Gas. D) All three. Show Answer Correct Answer: D) All three. 56. Which of the following chemical reactions involve combustion? A) A forest fire. B) Human digestion. C) A car using petrol. D) All of the above. Show Answer Correct Answer: D) All of the above. 57. Is the combustion reversable A) Yes. B) No. C) All the above. D) None of the above. Show Answer Correct Answer: B) No. 58. Unburnt carbon particles causes A) Throat problems. B) Brain infections. C) Stomach infection. D) Respiratory problems. Show Answer Correct Answer: D) Respiratory problems. 59. Ignition temperature of a fuel in air is ..... that in pure oxygen. A) More than. B) Equal to. C) Either more or less; depends on the type of fuel. D) Less than. Show Answer Correct Answer: A) More than. 60. Acid rain is caused by oxides of A) Sulphur, nitrogen. B) Phosphorous, carbon. C) Carbon, nitrogen. D) Sulphur, carbon. Show Answer Correct Answer: A) Sulphur, nitrogen. ← PreviousNext →Related QuizzesScience QuizzesClass 8 QuizzesClass 8 Science Chapter 6 Combustion And Flame Quiz 1Class 8 Science Chapter 6 Combustion And Flame Quiz 2Class 8 Science Chapter 6 Combustion And Flame Quiz 4 🏠 Back to Homepage 📘 Download PDF Books 📕 Premium PDF Books