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प्रश्न
Write true or false for a given statement.
On touching a lump of ice, we feel cold because some heat passes from our body to the ice.
विकल्प
True
False
उत्तर
True.
APPEARS IN
संबंधित प्रश्न
Fill in the blank
Heat transfer in solids is by ______
Explain briefly the process of heat transfer by radiation.
Give one example of heat transfer by radiation.
How does a fever get lowered by putting a cold compress on the forehead of a patient?
Why is the outer coat of the penguins of Antarctica black?
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 |
Heat is the transfer of energy between two objects at different temperatures.
When a liquid boils, energy is absorbed.
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.
