AP 8th Class Physical Science Bits Chapter 8 Combustion, Fuels and Flame with Answers

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AP State Syllabus 8th Class Physical Science Bits 8th Lesson Combustion, Fuels and Flame with Answers

Choose the correct answer.

Question 1.
The example for combustible material
A) sand
B) clay
C) alcohol
D) pebbles
Answer:
C) alcohol

Question 2.
The example for non-combustible material
A) Kerosene
B) Petrol
C) Diesel
D) Iron
Answer:
D) Iron

Question 3.
……….. gas supports combustion.
A) Oxygen
B) Hydrogen
C) Chlorine
D) Nitrogen
Answer:
A) Oxygen

Question 4.
Fire produced by oil cannot be controlled by
A) water
B) sodium carbonate
C) carbondioxide
D) none of these
Answer:
A) water

Question 5.
Fuel must be heated to its ……….. temperature before it starts burning.
A) Critical
B) Ignition
C) Melting
D) Freezing
Answer:
B) Ignition

Question 6.
The outermost zone of candle is ………… in colour.
A) blue
B) red
C) black
D) yellow
Answer:
A) blue

Question 7.
………… zone of candle is least hot.
A) Middle zone
B) Outermost zone
C) Dark zone
D) None of these
Answer:
C) Dark zone

Question 8.
The dark zone of candle is …………… in colour.
A) blue
B) black
C) red
D) yellow
Answer:
B) black

Question 9.
The gas needed for combustion among the following is
A) Argon
B) Oxygen
C) Carbon dioxide
D) Hydrogen
Answer:
B) Oxygen

Question 10.
The lowest temperature at which a substance catches fire is called its
A) Ignition temperature
B) Maximum temperature
C) Room temperature
D) Normal temperature
Answer:
A) Ignition temperature

Question 11.
The units of calorific value is
A) Newtons/grams
B) Newtons/kg
C) Kilo jouls/kg
D) Kilo jouls/gram
Answer:
C) Kilo jouls/kg

Question 12.
Spirit and petroleum turns into gas at
A) Room temperature
B) Ignition temperature
C) Maximum temperature
D) Normal temperature
Answer:
A) Room temperature

Question 13.
A chemical process in which material reacts with oxygen present in the air to generate heat is called
A) combustion
B) partial combustion
C) non combustion
D) none of these
Answer:
A) combustion

Question 14.
The material which undergo combustion is called ………. material.
A) non combustible
B) partial combustible
C) combustible
D) none of these
Answer:
C) combustible

Question 15.
The material which does not undergo combustion is called ………… material.
A) combustible
B) partial combustible
C) non combustible
D) none of these
Answer:
C) non combustible

Question 16.
………… substances have very low ignition temperature.
A) Inflammable
B) Flammable
C) Partial flammable
D) None of these
Answer:
A) Inflammable

Question 17.
Burning of gas is an example of …………. combustion.
A) spontaneous
B) rapid
C) regular
D) irregular
Answer:
B) rapid

Question 18.
…………. zone is the hottest part of the candle.
A) Innermost
B) Middle
C) Outermost
D) None of these
Answer:
C) Outermost

Question 19.
Middle zone of candle is ……….. in colour.
A) Blue
B) Red
C) Yellow
D) White
Answer:
C) Yellow

Question 20.
Spirit and petrol turn into …………. at room temperature.
A) solid
B) liquid
C) gas
D) none of these
Answer:
C) gas

Question 21.
…………. among these prevents burning.
A) Oxygen
B) Carbon dioxide
C) Both
D) None of these
Answer:
B) Carbon dioxide

Question 22.
The full form of LPG is
A) Liquefied Pilot Gas
B) Liquified Petroleum Gas
C) Liquid Petrol Gas
D) Liquid Potential Gas
Answer:
B) Liquified Petroleum Gas

Question 23.
Middle zone of candle ………… hot.
A) highest
B) moderate
C) least
D) none of these
Answer:
B) moderate

Question 24.
Dark zone of candle ………….. hot.
A) least
B) moderate
C) highest
D) none of these
Answer:
A) least

Question 25.
Among these not a combustible material ………….
A) petrol
B) diesel
C) kerosene
D) sand
Answer:
D) sand

Question 26.
Among these ………….. is a com-bustible material.
A) steel
B) iron
C) sand
D) petrol
Answer:
D) petrol

Question 27.
Explosion takes place in
A) lamps
B) lanterns
C) crackers
D) none of these
Answer:
B) lanterns

Question 28.
The colour of flame of candle at hottest zone is
A) Red
B) Blue
C) Yellow
D) White
Answer:
B) Blue

Question 29.
Choose correct option for matching.
Group – A — Group -B
1. Middle zone of candle gas — a) Liquid petrol
2. Outermost zone of candle hot — b) Moderately
3. Dark zone of candle natural gas — c) Compressed
4. CNG — d) hottest part
5. LPG — e) Least hot
A) 1 – b, 2 – d, 3 – e, 4 – c, 5 – a
B) 1 – a, 2 – b, 3 – c, 4 – d, 5 – e
C) 1 – b, 2 – c, 3 – d, 4 – e, 5 – a
D) 1 – c, 2 – d, 3 – e, 4 – a, 5 – b
Answer:
A) 1 – b, 2 – d, 3 – e, 4 – c, 5 – a

Question 30.
………… gas is released when potassium permanganate is heated.
A) Hydrogen
B) Chlorine
C) Oxygen
D) Nitrogen
Answer:
C) Oxygen

Question 31.
…………. release oxygen on heating.
A) Mercuric sulphate
B) Lead chloride
C) Potassium permanganate
D) Sodium chloride
Answer:
C) Potassium permanganate

Question 32.
What information does the figure gives us?

A) Necessity of air for burning
B) Ignition temperature
C) Combustion
D) Structure of flame
Answer:
A) Necessity of air for burning

Question 33.
The formula of potassium permangan ate is
A) K₂MnO₄
B) KMnO₄
C) MnO₂
D) KClO₃
Answer:
B) KMnO₄

Question 34.
………… is written on petrol tankers,
A) Flammable
B) Inflammable
C) Highly inflammable
D) None of these
Answer:
C) Highly inflammable

Question 35.
………… is used in matchsticks.
A) Potassium chloride
B) Sodium chloride
C) Antimony sulphide
D) Potassium sulphide
Answer:
C) Antimony sulphide

Question 36.
……….. is used in surface of match- stick,
A) White phosphorous
B) Red phosphorous
C) Yellow phosphorous
D) None of these
Answer:
B) Red phosphorous

Question 37.
Choose correct option for matching.
Group – A — Group – B
1. Combustible material — a) KJ/kg
2. Non-combustible burning material — b) Prevents
3. Carbondioxide — c) Petrol
4. Phosphorous — d) Sand
5. Calorific value — e) Stored in water
A) 1 – c, 2 – d, 3 – b, 4 – e, 5 – a
B) 1 – a, 2 – b, 3 – c, 4 – d, 5 – e
C) 1 – b, 2 – c, 3 – d, 4 – e, 5 – a
D) 1 – c, 2 – d, 3 – e, 4 – a, 5 – b
Answer:
A) 1 – c, 2 – d, 3 – b, 4 – e, 5 – a

Question 38.
Choose correct option for matching.
Group – A — Group – B
1. Low ignition temperatures — a) Matchstick
2. Crackers — b) Inflammable substances
3. Potassium permanganate — (c) Explosion
4. Antinomy sulphide — (d) Surface of match box
5. Red phosphorous — (e) Oxygen
A) 1 – b, 2 – c, 3 – e, 4 – a, 5 – d
B) 1 – a, 2 – b, 3 – c, 4 – d, 5 – e
C) 1 – b, 2-c, 3-d, 4-e, 5-a
D) 1 – c, 2 – d, 3 – e, 4 – a, 5 – b
Answer:
A) 1 – b, 2 – c, 3 – e, 4 – a, 5 – d

Question 39.
Among the following High Calorific valued substance is ……….

Answer:
C)

Question 40.
The liquid fuel used in homes is
A) CNG
B) LPG
C) Coal gas
D) None of these
Answer:
B) LPG

Question 41.
Burning of wood and coal causes severe ………… pollution.
A) water
B) land
C) air
D) none of these
Answer:
C) air

Question 42.
The type of combustion in which material suddenly burns into flames without the application of any external agent is called ………
A) Rapid combustion
B) Slow combustion
C) Spontaneous combustion
D) Explosion
Answer:
C) Spontaneous combustion

Question 43.
Burning of a matchstick is an example of ………… combustion.
A) spontaneous
B) rapid
C) explosion
D) none of these
Answer:
A) spontaneous

Question 44.
In which situations we are misusing the fuel resources while cooking in our daily life?
A) Cooking with out lid
B) Using more water while cooking
C) Leakages in pipes, burners and regu-lators
D) All the above
Answer:
D) All the above

Question 45.
Units of calorific value is
A) Kilo joule
B) Kilo joule – kilogram
C) Kilo joule / kilogram
D) Kilogram
Answer:
C) Kilo joule / kilogram

Question 46.
Geetha: Fire is necessary to burn a substance.
Harini: Sufficient temperature is necessary for burning.
Whom do you support?
A) Geetha
B) Harini
C) Both Geetha & Harini
D) Neither Geetha nor Harini
Answer:
B) Harini

Question 47.
Which causes less pollution?
Among the fuels that we use in our daily life.
A) Kerosene
B) LPG
C) Dung cakes
D) Wood
Answer:
B) LPG

Question 48.
Observe the following graph.

Which have same calorific value?
A) Coal, Diesel
B) Coal, Petrol
C) Hydrogen, Diesel
D) Petrol, Diesel
Answer:
D) Petrol, Diesel

Question 49.
The correct order of the following sentences is
1) Insert a glass tumbler over it
2) Then flickers and finally, flame goes off
3) Take a small burning candle and put it on a table
4) The candle continues to burn for some time
A) 3, 2, 1, 4
B) 3, 1, 4, 2
C) 3, 1, 2, 4
D) 3, 4, 2,1
Answer:
B) 3, 1, 4, 2

Question 50.
On placing an inverted tumbler over a burning candle, the flame extinguishers after sometime. This is because of non-availability of ….
A) Water vapours
B) Oxygen
C) Carbon dioxide
D) Wax
Answer:
B) Oxygen

Question 51.
Which one among the following is considered as the cleanest fuel?
A) Petrol
B) Diesel
C) Cow dung cake
D) Hydrogen gas
Answer:
D) Hydrogen gas

Question 52.
Clothes catch fire, the best way to extinguish the fire is to
A) Throw water on the clothes
B) Use fire extinguisher
C) Cover the person with a woolen blanket
D) Cover the person with a polythene sheet
Answer:
B) Use fire extinguisher

Question 53.
In villages, people use wood as fuel because ………
A) It is considered to be an ideal fuel
B) Of its easy availability and low cost
C) It is environment friendly
D) It catches fire very easily
Answer:
B) Of its easy availability and low cost

Question 54.
Which one of the following has the highest calorific value?
A) Kerosene
B) Biogas
C) LPG
D) Petrol
Answer:
C) LPG

Question 55.
One of the following substances is expected to have the highest ignition temperature
A) Kerosene
B) Petrol
C) Coal
D) Alcohol
Answer:
C) Coal

Question 56.
The following is not a combustile substance
A) Camphor
B) Glass
C) Straw
D) Alcohol
Answer:
B) Glass