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प्रश्न
Write true or false for a given statement.
Black surfaces are the poor absorbers of heat radiations.
विकल्प
True
False
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उत्तर
False.
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संबंधित प्रश्न
No medium is required for transfer of heat by the process of ______.
Fill in the blank
Heat transfer in liquids and gases is by ________.
Why is the freezing chest in a refrigerator fitted near its top?
Conduction of heat takes place through a ______ substance.
Why are the houses in Rajasthan painted white?
Heat is the transfer of energy between two objects at different temperatures.
When ice changes into a liquid, it absorbs energy.
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 a sheet of paper. Draw a spiral on it as shown in Figure. Cut out the paper along the line. Suspend the paper as shown in Figure above a lighted candle. Observe what happens. Think of an explanation.
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.
