Class 8 Science MCQ Combustion And Flame

Question :Which of the following is smoke free fuel:
(a) wood
(b) LPG
(c) charcoal
(d) coal

Question :Coal mainly contains:
(a) carbon
(b) nitrogen and Sulphur
(c) carbon, hydrogen and nitrogen
(d) none of these

Question :The fuel which replaces use of diesel and petrol as fuels in automobiles is:
(a) LPG
(b) biogas
(c) CNG
(d) none of these

Question :Which of following does not produce flame on burning:
(a) LPG
(b) charcoal
(c) paper
(d) kerosene

Question :Which of the following is best fuel for automobiles:
(a) petrol
(b) CNG
(c) diesel
(d) kerosene

Question :Which poisonous gas is formed as a result of incomplete combustion ?
(a) carbon monoxide
(b) coal gas
(c) carbon dioxide
(d) nitrogen oxide

Question :The natural solid fuel is:
(a) coal
(b) charcoal
(c) coke
(d) LPG

Question : When we heat water in a paper bowl over a candle, the paper does not catch fire because
(a)Paper is not inflamable
(b)Paper gets wet
(c) Due to water the ignition temperature of paper is not reached
(d)This is not possible

Question : When oil or petrol catches fire, water is not used to extinguish it because
(a)Water covers oil and oil burns under water layer which may not be noticeable
(b) Water is heavier than oil / petrol and so remains below the oil layer which continues to burn
(c)Water get mixed with oil and increases fire
(d)Water gets evaporated

Question : In combustion
(a) Both heat and light is produced
(b)Only heat is produced
(c)Only light is produced
(d)All are correct

Question : A person caught fire on clothes is wrapped with blanket because
(a)The person suddenly feels cold
(b)To hide the burnt body parts
(c)The person’s clothes gets burnt
(d) To reduce air supply and put fire off

Question : Ignition temperature is
(a)The maximum temperature at which a substance catches fire
(b) The minimum temperature at which a substance catches fire
(c)The temperature of burning substance
(d)The temperature in the substance when fire if put off

Question :Combustion is a
(a) Chemical process
(b) Physical process
(c) Chemical process and physical process
(d) None of the options

Question :Ignition temperature is
(a) Lowest temperature at catch fire
(b) Higher temperature at catch fire
(c) Any temperature
(d) None of the options

Question :CNG and LPG are the examples of
(a) Gaseous fuels
(b) Solid fuels
(c) Liquid fuels
(d) They are not fuels

Question : Explosion takes place because of
(a) Release of large amount of gas under pressure due to sudden reaction
(b)Release of large amount of heat
(c)Release of large amount of light
(d)None of the above

Question :There are following zones of a flame
(a) Three
(b) Two
(c) Four
(d) None of the options

Question :The products of combustion are
(a) Carbon dioxide and water
(b) Oxygen and water
(c) Only carbon dioxide
(d) Only oxygen

Question :The substances which have very low ignition temperature will
(a) Catch fire easily
(b) Will not catch fire
(c) Catch fire after some time
(d) None of the options

Question :Burning of charcoal in a closed room will produce
(a) Carbon monoxide
(b) Carbon dioxide
(c) Nitrogen dioxide
(d) All of these

Question :Coal burns with ______
(a) Only glow
(b) Flame
(c) Flame and only glow
(d) None of the options

Question :Like fuel the sun also provides heat and light. The process taking place in the sun is called
(a) Nuclear process
(b) Combustion
(c) Burning
(d) All of these

Question :Which substance give heat and light after combustion
(a) Fuel
(b) Flame
(c) Ombustion
(d) None of the options

Question :Which of the following has lower ignition temperature?
(a) Kerosene oil
(b) Vegetable oil
(c) Paper
(d) Wood

Question :The lowest temperature at which a Substance catches fire is called its
(a) Ignition temperature
(b) Critical temperature
(c) Melting point
(d) Boiling point

Question :Which one of the following is combustible?
(a) Paper
(b) Stone pieces
(c) Glass
(d) Iron nail

Question :Combustion is a
(a) Chemical process
(b) None of the options
(c) Both Chemical process and Physical process
(d) Physical process

Question :Which one of the following is fuel of our body?
(a) Food
(b) Water
(c) Diesel
(d) Petrol

Question :Fuel may be
(a) All of the options
(b) Gas
(c) Liquid
(d) Solid

Question :Combustion is a reaction in which a Substance reacts with
(a) Oxygen
(b) Chlorine
(c) Nitrogen
(d) Hydrogen

Question :Charcoal burns in air producing
(a) CO₂
(b) O₂
(c) H₂
(d) CO

Question :When magnesium ribbon burnt it produce
(a) Magnesium oxide
(b) Magnesium chloride
(c) Magnesium sulphate
(d) Magnesium hydroxide

Question :Which fuels are used for running automobiles?
(a) Diesel
(b) Charcoal
(c) Coal
(d) Wood

Question :Coal is not a fossil fuel.

Question :Wildlife and minerals are exhaustible natural resources.

Question :Coal mainly contains hydrogen.

Question :Unburnt carbon particles in air are dangerous pollutants causing respiratory problems.

Question :Decreased percentage of carbon dioxide in air has been linked to global warming.

Question :Water can be used to control fires involving electric equipment or oils.

Question :LPG is a better domestic fuel than wood.

Question :In the sun heat and light are produced by nuclear reactions.

Question :Petroleum is a dark oily liquid.

Question :CNG is Compressed Natural Gas.

Question :The hottest zone of the flame is outermost zone.

Question :A piece of charcoal burns in air and produces carbon monoxide.

Question :The ignition temperature of wood is lower than that of kerosene oil.

Question :LPG has more calorific value than wood.

Question :A goldsmith use the middle zone of a flame for melting gold, and silver.

Question :Burning of wood and coal causes ___________________ of air.

Question :___________________ is a tough, porous and black substance.

Question :A combustible substance cannot catch fire or bum as long as its temperature is lower than its ___________________ temperature.

Question :The unit of calorific value of a fuel is ___________________ .

Question :Cement is a ___________________ substance.

Question :The slow process of conversion of dead vegetation into coal is called ___________________ .

Question :The three essential requirements for producing fire are ___________________, ___________________ and ___________________ .

Question :LPG is ___________________ ___________________ ___________________ .

Question :Process of separation of different constituents from petroleum is called ___________________.

Question :___________________ is the rise in temperature of the environment of the earth.

Question :Fuels are stores of energy which of burning give ___________________ and ___________________.

Question :The colour of outermost zone is ___________________ .

Question :A liquid fuel, used in homes is ___________________ .

Question :Fuel must be heated to its ___________________ before it starts burning.

Question :Fire produced by oil cannot be controlled by ___________________ .

Question :The colour of innermost zone of the flame is ___________________.

Question :Fire brigade uses ___________________ to extinguish the fire.

Question :Incomplete combustion of a fuel gives poisonous ___________________ gas.

Question :Inflammable substances have very ___________________ ignition temperature.

Question :The substances which burn in air are called ___________________ .