TOPIC: HEAT
Q1. An iron rod at 300 C is dropped by chance into a bucket containing water at 300 C. In which direction the heat flow in this case? Justify your answer.
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Q2. Convection is not possible in solids. Why?
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Q.3.Heat from the sun heats up the earth, but the atmosphere does not get heated up.
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Q4. Water is a bad conductor of heat. But we heat water without any difficulty. How is it possible?
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Q.5.Discuss why wearing more layers of clothing during winter keeps us warmer than wearing just one thick piece of clothing?
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Q.6. Why is it advised not to hold the thermometer by its bulb while reading it?
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Q.7.A cold spoon is dipped into a cup of hot coffee. Will it transfer heat to its other end? If yes, then by which process?
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Q.8. Give reasons.
a) Ventilators are provided near the ceiling of a room rather than near the floor.
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b) Ice wrapped in sawdust does not melt.
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c) Evaporation of sweat causes cooling.
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d) Top of a roof made of asbestos is painted white.
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Q.9.A few sharp jerks are given to the clinical thermometer before using it. Why is it done so?
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Q10. While sitting around burning wood, by which mode of heat transmission do you receive heat energy? Why other modes of heat transmission do not play any significant role?
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Q11. Why is the handle of a pressure cooker covered with thick plastic?
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Q12.A marble tile would feel cooler as compared to a wooden tile on a winter morning. Why?
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Please click on below link to download CBSE Class 7 Science Heat Worksheet Set C