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प्रश्न
Why is the outer coat of the penguins of Antarctica black?
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उत्तर
Black is a good absorber or trapper of heat. So, in cold regions like Antarctica, the black outer coating of penguins helps them to absorb as much heat from the surroundings and keep their bodies warm.
संबंधित प्रश्न
Give two examples each of conductors and insulators of heat.
Look at Figure. Mark where the heat is being transferred by conduction, by convection and by radiation.
Stainless steel pans are usually provided with copper bottoms. The reason for this could be that ______.
Fill in the blank
Heat transfer in liquids and gases is by ________.
Select the correct alternative
If we add a lump of ice to a tumbler containing water,
Why is the freezing chest in a refrigerator fitted near its top?
The earth receives heat from the sun by ______.
What are the modes of heat transfer?
Why are heaters fitted near the floor and air conditioners near the ceiling of a room?
Match the items in column-I to the items in column-II
| Column-I | Column-II | ||
| 1. | Linear expansion | (a) | change in volume |
| 2. | Superficial expansion | (b) | hot body to cold body |
| 3. | Cubical expansion | (c) | 1.381 X 10-23 JK-1 |
| 4. | Cubical expansion | (d) | change in length |
| 5. | Boltzmann constant | (e) | change in area |
