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प्रश्न
Write true or false for a given statement.
Medium is necessary for the transfer of heat by radiation.
पर्याय
True
False
उत्तर
False.
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संबंधित प्रश्न
Look at Figure. Mark where the heat is being transferred by conduction, by convection and by radiation.
A wooden spoon is dipped in a cup of ice cream. Its other end ______.
Stainless steel pans are usually provided with copper bottoms. The reason for this could be that ______.
Write true or false for a given statement.
Black surfaces are the poor absorbers of heat radiations.
Fill in the blank
Heat transfer in liquids and gases is by ________.
Maximum heat is absorbed by a ______ coloured object.
Why is the outer coat of the penguins of Antarctica black?
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 |
Wrap a thin paper strip tightly around an iron rod. Try to burn the paper with candle while rotating the iron rod continuously. Does it burn? Explain your observation.
Take two similar transparent glass bottles having wide mouths. Put a few crystals of potassium permanganate or pour a few drops of ink in one bottle. Fill this bottle with hot water. Fill the other bottle with cold water. Cover the cold water bottle with a thick piece of paper such as a postcard. Press the postcard firmly with one hand and hold the bottle with the other hand. Invert the bottle and place it on top of the hot water bottle. Hold both the bottles firmly. Ask some other person to pull the postcard. Observe what happens. Explain.
