The humidity of a place:
Lies between 10% to 20%
Is always more than 50%
Is always less than 80%
Varies from time to time
Lime water turns milky when exposed to air and stirred. This shows that air contains:
Carbon dioxide
Hydrogen
Nitrogen
Oxygen
Smoke is an example of:
Liquid-in-gas mixture
Gas-in-solid mixture
Solid-in-gas mixture
Gas-in-liquid mixture
The percentage of nitrogen in air is:
21%
0.1%
54%
78%
Which of the following are the uses of air?
Generating electricity
Disposal of seeds
Flying of birds
All of these
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
Which of the following gases cause the harmful green house effect?
All the plants require nitrogen for:
Reproduction
Photosynthesis
Transpiration
Growth
The correct ascending order of gases as per their composition in air is:
Oxygen < carbon dioxide < nitrogen
Hydrogen < oxygen < nitrogen
Nitrogen < hydrogen < oxygen
Oxygen < Carbon dioxide < hydrogen
We can find tiny droplets of water on the outer surface of a steel glass containing cold water or ice. This shows that:
Steel contains air
Air contains water vapour
Cold water can seep through solids
