17)Combustion of a substance releases heat and ___.
a) oxygen
b) wood
c) light
d) water
18) The suspended particles released by combustion of coal in air may lead to a health disease.
Select the correct option.
a) Goitre
b) Arthritis
c) Asthma
d) Bone cancer
19 What is the main chemical component present in striking surface of a matchbox?
a) Potassium chlorate
b) Phosphorus
c) Potassium
d) Graphite
20) When a cracker is ignited, a sudden reaction takes place with the evolution of heat, light
and sound. Identify the type of combustion?
a) Random combustion
b) Rapid combustion
c) Spontaneous combustion
d) Explosion
21 The SI unit of the calorific value of a fuel is :-
a) N/kg
b) KJ/kg
c) KW/kg
d) J/kg
22 Which of the following factors are essential to ignite a fire?
a) All of these
b) Fuel
c) Air (oxygen)
d) Heat
23) Water cannot be used as a fire extinguisher to put out –
a) Burning charcoal b) Burning cloth
c) Burning oil
d) Burning wood
24 Fuel may bea) Solid
b) Liquid
c) Gas
d) All of these
25 The lowest temperature at which a Substance catches fire is called itsa) Boiling point
b) Melting point
c) Ignition temperature
d) Critical temperature
26 Fire extinguishera) Cut off the supply of air
b) Bring down the temperature of fuel
c) Both (a) & (b)
d) None of these
27.Unburnt carbon particles causes
a) Stomach infections
b) Respiratory problems
c)Brain infections
d) Throat problems
28 .Which of the following is/are carbon fuel
a) Wood
b) Coal
c) Petroleum
d) All of these
29 Acid rain is caused by oxides of
a) Sulphur, Nitrogen
b) Sulphur, Carbon
c) Carbon, Nitrogen
d) Phosphorous, Carbon
Answers
Answered by
4
Your answers:-
17. a) Oxygen
18. c) Asthma
19. b) Phosphorus
20. d) Explosion
21. b) kJ/kg
22. a) All of these
23. c) Burning Oil
24. d) All of these
25. c) Ignition temperature
26. c) Both a and b
27. b) Respiratory diseases
28. b) Coal
29. a) Sulphur, nitrogen.
Answered by
4
Answer:
19.Light
20.asthma
21.phosphorus
22.rapid combustion
23.kJ/kg
24.all of these
25.Ignition temperature
26. Both a and b
27.throat problem
28.coal
29.Sulphur, Nitrogen
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