Olympiad Science - Air around us
Exam Duration: 45 Mins Total Questions : 30
Which of the following processes need oxygen?
- (a)
Combustion
- (b)
Respiration
- (c)
Oxidation
- (d)
All of the above
Which of the following statements is true regarding the earth's atmosphere?
- (a)
It gets denser with an increase in the altitude.
- (b)
It gets thinner with an increase in the altitude.
- (c)
It remains the same.
- (d)
It contains no solid particles.
Mountaineers carry oxygen cylinders with them because
- (a)
oxygen supports combustion.
- (b)
oxygen is less at higher altitudes.
- (c)
more oxygen is needed to cook food.
- (d)
oxygen does not support combustion.
Which of the following can show the direction of the wind?
- (a)
An anemometer
- (b)
A wind mill
- (c)
A windvane
- (d)
A barometer
Plants require nitrogen for
- (a)
reproduction.
- (b)
photosynthesis.
- (c)
transpiration.
- (d)
their growth.
Which of the following gases cause the harmful greenhouse effect?
- (a)
Hydrogen
- (b)
Oxygen
- (c)
Carbon dioxide
- (d)
Nitrogen
The percentage of nitrogen in air is
- (a)
21%.
- (b)
0.1%.
- (c)
54%.
- (d)
78%.
Which of the following enables us to drink a liquid through a straw?
- (a)
Humidity
- (b)
Temperature
- (c)
Atmospheric pressure
- (d)
Composition of air
The correct ascending order of gases as per their composition in air is
- (a)
oxygen < carbon dioxide < nitrogen.
- (b)
hydrogen < oxygen < nitrogen.
- (c)
nitrogen < hydrogen < oxygen.
- (d)
oxygen < carbon dioxide < hydrogen.
Air is useful for
- (a)
generating electricity.
- (b)
the dispersal of seeds.
- (c)
bird's flight.
- (d)
all of the above
Which of the following statements is true regarding the properties of air?
- (a)
Air is a good conductor of electricity.
- (b)
Air is a good conductor of heat.
- (c)
Air is translucent in nature.
- (d)
The composition of air varies from place to place
Which of the following is NOT associated with air?
- (a)
Having a campfire
- (b)
Flying a paper aeroplane
- (c)
Blowing out candles on a birthday cake
- (d)
Sunbathing at the beach
What can be said about the nature of air?
- (a)
Air is heterogeneous
- (b)
Air is a compound
- (c)
Air is homogeneous
- (d)
Air is an alloy
Rita fixed a candle at the bottom of a trough containing water. After lighting the candle, she inverted a gas jar over it. What did she observe?
- (a)
The flame continued to burn and water rose in the jar.
- (b)
The flame was put off and water rose in the jar.
- (c)
The flame continued to burn and water became milky.
- (d)
The flame was put off and black smoke was deposited on the sides of the jar.
What is the percentage of carbon dioxide present in air?
- (a)
0.3%
- (b)
0.03%
- (c)
0.003%
- (d)
1%
Given below are some applications of compressed air.
(i) Tyres
(ii) Sprayers
(iii) Gas cylinders
In which of the following is compressed air used?
- (a)
Only (i) and (ii)
- (b)
Only (ii) and (iii)
- (c)
Only (i) and (iii)
- (d)
(i), (ii) and (iii)
The amount of water vapour in air is greater in
- (a)
the rainy season.
- (b)
the dry season.
- (c)
the summer season.
- (d)
the autumn season.
In the given figure, a burning candle is kept in the trough containing water. It is put off after some time when covered by an inverted gas jar.
What can be concluded from the above activity?
- (a)
Oxygen is l/5th the volume of air.
- (b)
The ratio of oxygen and nitrogen in air is 1:4.
- (c)
Oxygen is required for burning the candle.
- (d)
All of the above
Which of the following is the most abundant element in the earth's crust?
- (a)
Nitrogen
- (b)
Oxygen
- (c)
Silicon
- (d)
Hydrogen
Which of the following is true about air?
(i) Air is a mixture of several gases.
(ii) Air exerts pressure.
(iii) The composition of air is constant in all places.
- (a)
Only (i) and (ii)
- (b)
Only (ii) and (iii)
- (c)
Only (i) and (iii)
- (d)
(i), (ii) and (iii)
Carbon dioxide gas can be tested by using
(i) blue litmus paper.
(ii) lime water.
(iii) burning splinter
- (a)
Only (i) and (ii)
- (b)
Only (ii) and (iii)
- (c)
Only (i) and (iii)
- (d)
(i), (ii) and (iii)
Which of the following gases in air helps burning?
- (a)
Oxygen
- (b)
Nitrogen
- (c)
Carbon dioxide
- (d)
Methane
In an experiment shown by the class teacher, the side of the ruler which holds the inflated balloon dips as compared to the balloon without air.
What is the conclusion drawn from this experiment?
- (a)
Balloon with air has greater force of gravity.
- (b)
Air has definite mass.
- (c)
Masses of the balloons are different.
- (d)
Balloon has more matter than air.
Which of the following methods need air?
- (a)
Hand picking
- (b)
Sieving
- (c)
Winnowing
- (d)
Filtration
We cannot feel the pressure of atmosphere because
- (a)
pressure increases with decrease in altitude.
- (b)
pressure decreases with increase in altitude
- (c)
pressure acts equally in all directions.
- (d)
pressure difference between atmosphere and inside our body is small.
An experiment was set up by placing a burning candle in a trough of water. A large graduated cylinder was inverted on it.
Why does the burning candle get extinguished?
- (a)
The cylinder is made up of glass
- (b)
The candle was not of good quality
- (c)
The oxygen in the cylinder has been used up
- (d)
All of these
An experiment was set up by placing a burning candle in a trough of water. A large graduated cylinder was inverted on it.
Why doesn't the water level reach up to the top of the inverted cylinder?
- (a)
This space is occupied by oxygen
- (b)
This space is occupied by carbon dioxide
- (c)
This space is occupied by water vapour
- (d)
This space is occupied by nitrogen
When a beam of sunlight filters through a small opening in a room, we see small particles randomly moving about. These particles are of
- (a)
nitrogen
- (b)
water vapour
- (c)
carbon dioxide
- (d)
dust.
When an object catches fire, people wrap a woollen blanket over the burning object. This is done to
- (a)
cut off carbon dioxide
- (b)
cut off oxygen supply
- (c)
save other costly things.
- (d)
wool cannot catch fire.
Water contains air which is used by aquatic organisms. This is seen when we heat water and the tiny bubbles of air appear. If the boiled water is kept in an air tight container for some time and is then reheated we will find that
- (a)
same amount of air bubbles appear
- (b)
more amount of air bubbles appear.
- (c)
no bubbles of air appear
- (d)
none of these.