Extra 40 MCQs with answers from Chapter:15 Air Around Us of Class 6 Science (CBSE):-
What is the major component of air?
a) Oxygen
b) Nitrogen
c) Carbon dioxide
d) Hydrogen
Answer:
b) Nitrogen
What percentage of air is nitrogen?
a) 21%
b) 78%
c) 1%
d) 50%
Answer:
b) 78%
Which gas is essential for respiration?
a) Nitrogen
b) Carbon dioxide
c) Oxygen
d) Hydrogen
Answer:
c) Oxygen
Which gas is used by plants for photosynthesis?
a) Oxygen
b) Carbon dioxide
c) Nitrogen
d) Argon
Answer:
b) Carbon dioxide
What is the role of nitrogen in the atmosphere?
a) Supports burning
b) Used for respiration
c) Dilutes oxygen and prevents rapid burning
d) Increases temperature
Answer:
c) Dilutes oxygen and prevents rapid burning
Which gas is released by plants during photosynthesis?
a) Oxygen
b) Carbon dioxide
c) Nitrogen
d)
Sulphur
dioxide
Answer:
a) Oxygen
What is the function of carbon dioxide in the atmosphere?
a) Helps in burning
b) Maintains Earth’s temperature
c) Makes up the majority of air
d) Helps in breathing
Answer:
b) Maintains Earth’s temperature
Which gas forms the second-largest portion of air?
a) Oxygen
b) Nitrogen
c) Carbon dioxide
d) Argon
Answer:
a) Oxygen
Which component of air is necessary for combustion?
a) Oxygen
b) Nitrogen
c) Carbon dioxide
d) Water vapor
Answer:
a) Oxygen
What is the percentage of oxygen in air?
a) 21%
b) 78%
c) 1%
d) 50%
Answer:
a) 21%
What is air made up of?
a) Only oxygen
b) Only nitrogen
c) A mixture of gases
d) Only carbon dioxide
Answer:
c) A mixture of gases
What is the importance of water vapor in air?
a) It helps in breathing
b) It forms clouds and rain
c) It helps in burning
d) It dilutes oxygen
Answer:
b) It forms clouds and rain
Which process removes carbon dioxide from the air?
a) Respiration
b) Photosynthesis
c) Combustion
d) Decay
Answer:
b) Photosynthesis
Which gas is a major pollutant in the air?
a) Oxygen
b) Nitrogen
c) Carbon monoxide
d) Water vapor
Answer:
c) Carbon monoxide
Which property of air allows birds and airplanes to fly?
a) Air is
colourless
b) Air has pressure
c) Air contains oxygen
d) Air is present everywhere
Answer:
b) Air has pressure
What is the role of the ozone layer?
a) Increases air pollution
b) Absorbs harmful UV rays from the Sun
c) Produces oxygen
d) Reduces wind speed
Answer:
b) Absorbs harmful UV rays from the Sun
Which gas is responsible for global warming?
a) Oxygen
b) Carbon dioxide
c) Nitrogen
d) Argon
Answer:
b) Carbon dioxide
Which gas do plants take in at night?
a) Oxygen
b) Nitrogen
c) Carbon dioxide
d) Argon
Answer:
a) Oxygen
Why do mountaineers carry oxygen cylinders?
a) To breathe in low oxygen areas
b) To prevent dehydration
c) To remove carbon dioxide
d) To maintain temperature
Answer:
a) To breathe in low oxygen areas
How does air pollution affect humans?
a) Improves breathing
b) Causes respiratory diseases
c) Increases oxygen levels
d) Increases rainfall
Answer:
b) Causes respiratory diseases
Which component of air is essential for burning?
a) Nitrogen
b) Oxygen
c) Carbon dioxide
d) Water vapor
Answer:
b) Oxygen
The layer of air surrounding the Earth is called?
a) Hydrosphere
b) Biosphere
c) Atmosphere
d) Lithosphere
Answer:
c) Atmosphere
What is the main cause of air pollution?
a) Natural disasters
b) Industrial emissions and vehicle smoke
c) Ocean waves
d) Photosynthesis
Answer:
b) Industrial emissions and vehicle smoke
Which gas is used by plants to make food?
a) Oxygen
b) Nitrogen
c) Carbon dioxide
d) Hydrogen
Answer:
c) Carbon dioxide
Which process increases oxygen in the air?
a) Respiration
b) Photosynthesis
c) Burning
d) Digestion
Answer:
b) Photosynthesis
Which component of air is responsible for rusting?
a) Carbon dioxide
b) Oxygen
c) Nitrogen
d) Hydrogen
Answer:
b) Oxygen
What is the role of dust particles in air?
a) Cause pollution only
b) Help in cloud formation
c) Absorb oxygen
d) Convert oxygen into nitrogen
Answer:
b) Help in cloud formation
How do fish breathe in water?
a) Using their skin
b) Using their lungs
c) Using gills to extract oxygen from water
d) By swallowing air
Answer:
c) Using gills to extract oxygen from water
Which gas is used in fire extinguishers?
a) Oxygen
b) Nitrogen
c) Carbon dioxide
d) Hydrogen
Answer:
c) Carbon dioxide
What is wind?
a) Moving water
b) Moving air
c) Moving sunlight
d) Moving trees
Answer:
b) Moving air
How do animals take in oxygen?
a) Only through lungs
b) Only through gills
c) Through lungs, gills, and skin (depending on species)
d) They do not need oxygen
Answer:
c) Through lungs, gills, and skin (depending on species)
What happens when air is heated?
a) It expands
b) It contracts
c) It disappears
d) It turns into liquid
Answer:
a) It expands
What is the main function of the troposphere?
a) Absorbs UV radiation
b) Contains most weather activities
c) Produces oxygen
d) Forms the ozone layer
Answer:
b) Contains most weather activities
34. How is oxygen added to the air?
a) By burning fuels
b) By respiration
c) By photosynthesis
d) By wind movement
Answer: c) By photosynthesis
35. Why does a balloon burst when overinflated?
a) Due to air expanding inside
b) Due to loss of oxygen
c) Due to external pressure
d) Because air turns into a solid
Answer: a) Due to air expanding inside
36. How is wind formed?
a) Due to rotation of the Earth
b) Due to the Sun’s heat creating pressure differences
c) Due to rainfall
d) Due to increase in oxygen levels
Answer: b) Due to the Sun’s heat creating pressure differences
37. What happens to air pressure as we go higher up in the atmosphere?
a) It increases
b) It remains the same
c) It decreases
d) It fluctuates randomly
Answer: c) It decreases
38. How does air help birds to fly?
a) Air pushes them forward
b) The movement of wings creates air resistance
c) Air provides lift and support
d) Air does not help birds to fly
Answer: c) Air provides lift and support
39. Which gas is used in respiration by humans and animals?
a) Carbon dioxide
b) Nitrogen
c) Oxygen
d) Argon
Answer: c) Oxygen
40. How does air pollution affect plants?
a) It improves plant growth
b) It helps plants produce more oxygen
c) It damages leaves and reduces growth
d) It makes plants more resistant to drought
Answer: c) It damages leaves and reduces growth
