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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
Look at Figure. Mark where the heat is being transferred by conduction, by convection and by radiation.
Write true or false for a given statement.
Medium is necessary for the transfer of heat by radiation.
Fill in the blank
Heat transfer in solids is by ______
Select the correct alternative
The vacuum kept in between the walls of a thermos flask reduces the heat transfer by
Explain briefly the process of heat transfer by radiation.
______ of heat does not require a medium.
Conduction of heat takes place through a ______ substance.
Explain which mode of heat transfer causes sea breezes and land breezes.
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 |
When a liquid boils, energy is absorbed.
