Glass panes usually appear hazy because
Water vapour settling on the tiny dust particles
Of chemical reactions
It is property of all transparent substances
They are old
Which of the following can show the direction of wind ?
Anemometer
Wind vane
Wind mill
Barometer
Which of the following is combustible ?
Oxygen
Carbon dioxide
Hydrogen
All
Mountaineers carry oxygen cylinders with them because
Oxygen supports combustion
Air becomes thinner as we go higher
Air is dense but lacks oxygen in mountains
None of these
State the wrong statement from the following sentences.
Air has no force
Air occupies space
Air has weight.
Air has no definite shape
Which of the following plays a very important role in the oxygen cycle ?
Birds
Animals
Plants
Soil
The percentage of nitrogen in air is
21%
0.1%
54%
78%
Air is one of the main components which help in the _______________of seeds.
germination
reproduction
pollination
growth
Which of the following statements is true regarding Earth's atmosphere ?
It gets denser with increase in altitude
It gets thinner with increase in altitude
Its thickness is at least one fourth the radius of the Earth
It contains no solid particles
We can find tiny droplets of water on the outer surface of a steel tumbler containing cold water or ice. This shows that
Steel contains air
Air contains water vapour
Cold water can seep through solids
