In which of the following sentences are incorrect?

The substances which give very low ignition, temperature and can easily catch fire with a flame, are called inflammable substances.

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:

Due to incomplete combustion of fuel, copper vessel was getting blackened from outside.

Paheli is writing some statements. She wants to know in which of the following statements is or are incorrect?

Matchstick does not burn by itself. A matchstick is lighted by rubbing it on the rough surface provided on the side of the matchbox. The heat produced by friction arises the temperature of the chemicals present on the matchstick head to their ignition temperature. Due to this, the chemicals present on the head of the matchstick catch fire and the matchstick starts burning.

Consider the following statements, choose the incorrect one:

Here, all the statements are correct. Hence, your answer will be option [D].

Which of the following represents the correct statements?

Here, all the statements are correct. Hence, your answer will be option [D].

Which one among the following is considered as the cleanest fuel?

Hydrogen gas is considered as cleanest fuel. Unlike carbon-based fuels, hydrogen produces no harmful by-products on combustion. Only energy and clean water are produced.

Paheli is writing some statement which is given by her teacher. Would you help him to choose the incorrect statements?

Wood, paper, CNG are combustible substances. Substances which easily catch fire are combustible substances. Such as paper, coal, wood etc. Substances which do not catch fire readily are non-combustible substances. Such as sand, water, etc.

Consider the following statements and choose the correct one:

Here, all the statements are correct. Hence, your answer will be option [D].

In villages, people use wood as fuel because:

In villages, people use wood as fuel because of its easy availability and low cost.

The calorific value of a fuel is expressed in the unit called:

The calorific value of a fuel is expressed in the unit of kilojoule per kilogram (kJ/kg).

Which of the following statement is or are incorrect?

The fire can be extinguished in three ways by; removing of fuel or combustible substances, by removing the heat or by cutting of the supply of oxygen which is present in air.

Choose the incorrect statement from the following: “Forest fires are usually due to …”

Forest fires are not due to cutting of trees.

Consider the following statements, choose the incorrect one:

Respiration is a kind of “slow” combustion of food which takes place in the body to produce heat energy.

Boojho is writing some statements about polyester. In which of the following statements is or are incorrect? Help him.

The heat and light produced in the sun are not due to ordinary combustion which takes place in the presence of oxygen of air. In the sun, heat and light are produced due to nuclear reactions in which “hydrogen is converted into helium” with the release of heat and light.

Choose the correct statement about inflammable substance from the following:

Inflammable substances have low ignition temperature and can and catch fire easily.

Consider the following statements and choose the incorrect statement(s):

Those substances which can undergo combustion are called combustible substances.

Boojho is writing some statements about polyester. In which of the following statements is or are incorrect? Help him.

Here, all the statements are correct. Hence, your answer will be option [D].

Consider the following statements, choose the incorrect one:

It is very easy to burn a heap of dry leaves. We know that it is difficult to burn a heap of green leaves. The green leaves contain a lot of water. This water does not allow the green leaves to get heated to their ignition temperature easily and makes the burning of green leaves difficult. On the other hand, dry leaves do not contain water, they get heated to their ignition temperature easily and hence can catch fire easily.

If a person's clothes catch fire the best way to extinguish the fire is to:

Cover the person with a woollen blanket so that the supply of air to the burning clothes is cutoff and hence, the burning of fire stops.

On placing an inverted tumbler over a burning candle, the flame extinguishes after sometime. This is because of non-availability of:

The flame extinguishes because of non-availability of oxygen. Air or oxygen is necessary for combustion.

Boojho is writing some statements but he confused to know whether the statements are correct or not? Would you help him?

Here, all the statements are correct. Hence, your answer will be option [D].

Consider the given statements and choose the incorrect one:

The spontaneous combustion which take place in nature are very dangerous.

The substance that does not burn with flame is:

Charcoal is a solid fuel which does not vaporize on heating. So, charcoal does not burn by producing a flame. It only glows on combustion.

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:

It has a high calorific value. Hence, it produces a large amount of heat.

A substance which reacts with oxygen giving heat is called a combustible substance. Which one of the following is a combustible substance?

Wood is a combustible substance. It is a solid fuel and produces smoke during combustion.

In which of the following sentences are incorrect?

The substances which give very low ignition, temperature and can easily catch fire with a flame, are called inflammable substances.

Class 8 Science Chapter 6 MCQ

Class 8 Science Chapter 6 MCQ (Multiple Choice Questions) of Combustion and Flame. After doing NCERT Books, these questions help in revising the chapter for tests and exams. There are more than 80 questions divided into sets of 10 questions each.

These questions cover all the important topic and intext questions from NCERT Books. Some exercises questions are also included in these practice tests.

Class 8 Science Chapter 6 MCQ Online Tests for 2020-2021

Class: 8	Science
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 2020-2021 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.

Magnesium ribbon on burning in air produces:

[A]. Magnesium oxide water and light

[B]. Magnesium oxide and heat

[C]. Magnesium oxide heat and light

[D]. Magnesium oxide water and heat

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

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.

View Answer

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.

View Answer

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.

View Answer

The substance expected to have the highest ignition temperature out of the following is:

[A]. Kerosene

[B]. Petrol

[C]. Coal

[D]. Alcohol

View Answer

Mohan is writing some statements, choose the correct statements and help him:

[A]. When water is thrown on a burning substance it gets cooled below its ignition temperature and stops burning.

[B]. The fire produced by burning oil (frying pan) and petrol (petrol pumps, oil tanks etc.) cannot be extinguished by using water.

[C]. The fire caused by electrical short circuit in an electrical appliance or in electrical wiring should not be extinguished by throwing water.

[D]. All the above

View Answer

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.

View Answer

Which of the following is not a combustible substance?

[A]. Camphor

[B]. Glass

[C]. Straw

[D]. Alcohol

View Answer

Q10

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.

View Answer

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Class 8 Science Chapter 6 MCQ

Class 8 Science Chapter 6 MCQ Online Tests for 2020-2021

Class 8 Science Chapter 6 MCQ with Answers and Explanation

Magnesium ribbon on burning in air produces:

Choose the incorrect statement from the following: “A good fuel is one which …

In which of the following statements is or are correct?

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?

Boojho is writing some sentences about condition for combustion. Choose the correct sentences and help him:

The substance expected to have the highest ignition temperature out of the following is:

Mohan is writing some statements, choose the correct statements and help him:

Paheli is writing some statements but she confused to know whether the statements are incorrect or not? Would you help her?

Which of the following is not a combustible substance?

Boojho is writing about the factors of “Global warming”. Considered the sentences written by Boojho and choose in correct one(s):

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High School

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Class 8 Science Chapter 6 MCQ

Class 8 Science Chapter 6 MCQ Online Tests for 2020-2021

Class 8 Science Chapter 6 MCQ with Answers and Explanation

Magnesium ribbon on burning in air produces:

Choose the incorrect statement from the following: “A good fuel is one which …

In which of the following statements is or are correct?

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?

Boojho is writing some sentences about condition for combustion. Choose the correct sentences and help him:

The substance expected to have the highest ignition temperature out of the following is:

Mohan is writing some statements, choose the correct statements and help him:

Paheli is writing some statements but she confused to know whether the statements are incorrect or not? Would you help her?

Which of the following is not a combustible substance?

Boojho is writing about the factors of “Global warming”. Considered the sentences written by Boojho and choose in correct one(s):

Feedback and Suggestion

NCERT Solutions

High School

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