Advertisements
Advertisements
Question
Explain the following observations very briefly
A firki does not rotate in a closed area.
Advertisements
Solution
A firki rotates due to the air movement present in the surrounding and a closed area doesn’t support air movement. Hence, a firki will rotate only when placed in an open area due to the presence of moving air all around.
APPEARS IN
RELATED QUESTIONS
What was the ancient belief regarding the nature of matter ?
What do you observe when a beam of light is allowed to enter in a closed dark room through a small hole.
What is air pollution?
Fill in the blank
Air is a ______ of gases
Tick (√) the correct alternative from the choice given for the following statement.
The gases which cause acid rain are
With whom should I pair up?
| Group A | Group B | ||
| (1) | Air | (a) | Excretion |
| (2) | Water | (b) | Scattering of light |
| (3) | Soil | (c) | Plasticity |
Explain the term ‘air pollution’, with reference to air quality. State the sources of a few main pollutants.
Match the statements in List I with the correct answer from List II.
| List I | List II |
| 1. The constituent of air which is around 0.02% | A: Nitrogen |
| 2. The constituent of air which is inert or unreactive | B: Oxygen |
| 3. The constituent of air which is non-combustible, but supports combustion. |
C: Sulphur dioxide |
| 4. A pollutant in air responsible for acid rain | D: Carbon dioxide |
| 5. The main rare gas present in air. | E: Argon |
Draw a neat labelled diagram for the following experiment.
To determine the component of air used up in burning, by using phosphorus and a bell jar.
Do sailors need the help of wind to sail?
