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प्रश्न
What do you observe when a beam of light is allowed to enter in a closed dark room through a small hole.
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उत्तर
We will observe randomly moving dust particles in the beam of light. This confirms the presence of dust particles in the air.
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संबंधित प्रश्न
Match the statements in Column A, with those in Column B.
| Column A | Column B |
| 1. Largest Constituent of air, which dilutes the activity of oxygen. |
(a) Oxygen |
| 2. A gas used for filling weather observation balloons. | (b) carbon acid |
| 3. An acid formed by the dissolution of sulphur dioxide gas in water. | (c) Sulphur acid |
| 4. An acid formed by the dissolution of carbon dioxide in water. | (d) Helium |
| 5. A gas vital for respiration. | (e) Nitrogen |
Define the following:
Respiration
Name the processes which maintain the balance between oxygen and carbon dioxide in the air. How is it done?
Tick (√) the correct alternative from the choice given for the following statement.
Fuels which do not leave any residue on burning are
Describe a simple experiment with the help of a diagram to show that Air has mass
Water does not have a ______ but has definite ______ and ______.
What will happen if the amount of water vapour in the air increases.
Wind does not help in the movement of which of the following?
A list of words is given in a box. Use appropriate words to fill up the blank in the following statement.
Air is a ______ of some gases.
Paheli kept some water in a beaker for heating. She observed that tiny bubbles appeared before the water started to boil. She boiled the water for about 5 minutes and filled it in a bottle up to the brim and kept the bottle air tight till it cooled down to room temperature.
Do you think tiny bubbles will appear on heating the water taken out from the bottle? Justify your answer.
