Class 8 Science Chapter 6 MCQ Online Tests for 2021-2022
|Chapter 6:||Combustion and Flame|
|Contents:||MCQ Online Tests with Explanation|
Class 8 Science Chapter 6 MCQ with Answers and Explanation
MCQ Online tests for class 8 Science chapter 6 are given below with answer and explanation. All the questions are taken from Latest CBSE NCERT Books for 2021-2022 and are important for examination point of view. These MCQ Quiz questions takes hardly 30 minutes to complete and help to score better than ever.
Shyam was cooking potato curry on a chulha. To his surprise, he observed that the copper vessel was getting blackened from outside. It may be due to:
[A]. Proper combustion of fuel
[B]. Improper cooking of potato curry
[C]. Improper combustion of fuel
[D]. Burning of copper vessel
Paheli is writing some statements. She wants to know in which of the following statements is or are incorrect?
[A]. The substance which vaporize during burning give flame.
[B]. Diesel is a combustible substance.
[C]. Glass is a non-combustible material.
[D]. Matchstick burn by itself.
Consider the following statements, choose the incorrect one:
[A]. Some substances on combustion produces heat and flame.
[B]. The amount of heat energy produced on complete combustion of 1 kg of fuel is called its calorific value.
[C]. When CNG burns, it produces harmful products in very small amount.
[D]. None of the above.
Choose the incorrect statement from the following: “A good fuel is one which …
[A]. Is readily available
[B]. Produces a large amount of heat
[C]. Leaves behind many and desirable substances
[D]. Burns easily in air at a moderate rate
Which of the following represents the correct statements?
[A]. Outer zone of complete combustion is the hottest part which is blue in colour.
[B]. Middle zone of partial combustion is the moderate hot part which is yellow in colour.
[C]. Innermost zone of unburnt wax vapours is least hot which is black in colour.
[D]. All the above
Consider the following statements and choose the correct one:
[A]. The substance which have very low ignition temperature and can easily catch fire with a flame are called inflammable substance.
[B]. The amount of heat energy produced on complete combustion of 1 kg of a fuel is called its calorific value.
[C]. Inflammable substance have very low ignition temperature.
[D]. All the above
In villages, people use wood as fuel because:
[A]. It is considered to be an ideal fuel
[B]. Of its easily available and low cost
[C]. It is environment friendly
[D]. It catches fire easily
In which of the following statements is or are correct?
[A]. A physical process in which a substance reacts with oxygen to give off heat is called combustion.
[B]. Water is the best extinguisher for fire involving electrical equipment.
[C]. Alcohol, CNG and LPG are inflammable substances.
[D]. Increased concentration of nitrogen in air is believed to cause global warming.
Boojho appeared in class test where he wrote some statements but he confused to know the incorrect statement. Would you help him to know that?
[A]. Greater the calorific value, better is the fuel.
[B]. Middle zone is the hottest zone of a flame.
[C]. The substances which vaporize during burning give flame.
[D]. Calorific value of wood is higher than that of coal.
Choose the incorrect statement from the following: “Forest fires are usually due to …”
[A]. Carelessness of humans
[B]. Heat of sun
[C]. Cutting of trees
[D]. Lightning Strike
Boojho is writing some statements about polyester. In which of the following statements is or are incorrect? Help him.
[A]. In the sun, heat and light are produced due to nuclear reactions.
[B]. The heat and light produced in the sun are ordinary combustion as like fire.
[C]. A substance which can burn are called combustible substances.
[D]. When a magnesium ribbon burns it combines with oxygen of air to form magnesium oxide and liberate heat and light.
Choose the correct statement about inflammable substance from the following:
[A]. Low ignition temperature and cannot catch fire easily.
[B]. High condition temperature and can catch fire easily.
[C]. Low ignition temperature and can catch fire easily.
[D]. High ignition temperature and cannot catch fire easily.
Consider the following statements and choose the incorrect statement(s):
[A]. The burning of magnesium in air to produce heat and light is a combustion process.
[B]. When charcoal burns, then the carbon of charcoal combines with oxygen of air to form carbon dioxide.
[C]. A combustible substance is also called a fuel.
[D]. Those substances which can undergo combustion are called non-combustible substances.
Boojho is writing some sentences about condition for combustion. Choose the correct sentences and help him:
[A]. Heating the combustible substance to its ignition temperature.
[B]. Presence of a supporter of combustion like air or oxygen.
[C]. Presence of a combustible substance.
[D]. All the above.
The substance expected to have the highest ignition temperature out of the following is:
Which of the following statement is or are incorrect?
[A]. A small fire can be extinguished by throwing sand or soil over it.
[B]. If the clothes of person working in the kitchen catch fire, the person is immediately covered with a blanket.
[C]. The combustion reaction in which a large amount of heat and light produced in a short time is called rapid combustion.
[D]. Any fire needs heat and combustible materials to occur.
On placing an inverted tumbler over a burning candle, the flame extinguishes after sometime. This is because of non-availability of:
[B]. Water vapors
[C]. Carbon dioxide
Boojho is writing some statements but he confused to know whether the statements are correct or not? Would you help him?
[A]. Rapid combustion is that type of combustion in which a large amount of heat and light are produced in a short time.
[B]. Spontaneous is that type of combustion in which reaction occurs on its own without helping of heat.
[C]. Explosive combustion is that type of combustion in which a large amount of heat, light and sound are produced in very fast way.
[D]. All the above.
Consider the given statements and choose the incorrect one:
[A]. The immediate burning of cooking gas store is an example of rapid combustion.
[B]. The burning of white phosphorus is an example of spontaneous combustion.
[C]. Bursting of crackers is an example of explosive combustion.
[D]. The spontaneous combustion which take place in nature are less dangerous.
Paheli is writing some statements but she confused to know whether the statements are incorrect or not? Would you help her?
[A]. Fuel is a material which is burnt to produce heat.
[B]. Different fuels produce different amount of heat on burning.
[C]. The amount of heat produced by the complete burning of 1 kg of a fuel is called its calorific value.
[D]. The calorific value of coal is much higher than the calorific value of LPG.
Saumya is writing about “ideal fuel” as ideal fuel is cheap easy to transfer and readily available in the market. Choose in correct sentences written by Saumya:
[A]. It does not produce harmful gases or do not leave any residue after burning.
[B]. It has a proper ignition temperature.
[C]. It can burn easily in air at a moderate rate.
[D]. It has a low calorific value for proper burning.
Which of the following is not a combustible substance?
Which of the following has the highest calorific value?
A substance which reacts with oxygen giving heat is called a combustible substance. Which one of the following is a combustible substance?
[A]. Iron Nail
Boojho is writing about the factors of “Global warming”. Considered the sentences written by Boojho and choose in correct one(s):
[A]. The burning of fuels like wood, coal and petroleum releases unburnt carbon particles in air.
[B]. Incomplete combustion can create carbon mono oxide, which is very poisonous.
[C]. Burning of petrol and diesel engine of vehicles releases nitrogen oxides into the air.
[D]. None of the above.
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