done 7th Heat

• question_answer1)
  How do we find out how hot an object really is?  
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• question_answer2)
  Is the body temperature of every person \[37{}^\circ C\]?
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• question_answer3)
  How do we measure the temperature of other object rather than human body?  
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• question_answer4)
  The clinical thermometer is not used to measure high temperature, why?  
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• question_answer5)
  Why does the mercury not fall or rise in a clinical thermometer when taken out of the mouth?  
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• question_answer6)
  When a pan is removed from the fire, why does it cool down?
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• question_answer7)
  How does the heat travel in air? In which direction, does the smoke go?
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• question_answer8)
  Why are you advised to use an umbrella when you go out in the sun?
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• question_answer9)
  Why we wear dark coloured clothes in winter and light coloured clothes in summer?
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• question_answer10)
  Why it is preferred to use two thin blankets rather than one thick blanket?  
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• question_answer11)
  State similarities and differences between the laboratory thermometer and the clinical thermometer.
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• question_answer12)
  Give two examples each of conductors and insulator of heat.
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• question_answer13)
  Fill in the blanks. (a) The hotness of a body is determined by .......... (b) Temperature of boiling water cannot be measured by a ......... thermometer. (c) Temperature is measured in degree ......... . (d) No medium is required for transfer of heat by the process of......... . (e) A cold steel spoon is dipped in a cup of hot milk. It transfer heat to its other end by the process of ......... . (f) Clothes of ......... colour absorb heat better than clothes of light colours.  
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• question_answer14)
  Match the following.  

  (a)	Land breeze blows during	(i)	Summer
  (b)	Sea breeze blows during	(ii)	Winter
  (c)	Dark coloured clothes are preferred during	(iii)	Day
  (d)	Light coloured clothes are preferred during	(iv)	Night

   
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• question_answer15)
  Discuss why wearing more layers of clothing during winter keeps us warmer than wearing just one thick piece of clothing.
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• question_answer16)
  Look at the figure, mark where the heat is being transferred by conduction, convection and radiation.  
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• question_answer17)
  In places of hot climate, it is advised that the outer walls of house be painted white. Explain.
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• question_answer18)
  One litre water at \[30{}^\circ C\]is mixed with one litre of water \[50{}^\circ C\]. The temperature of the mixture will be (a) \[80{}^\circ C\] (b) more than \[50{}^\circ C\] but less than \[80{}^\circ C\] (c) \[20{}^\circ C\] (d) between \[30{}^\circ C\]and \[50{}^\circ C\]  
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• question_answer19)
  An iron ball at \[40{}^\circ C\] is dropped in a mug containing water at \[40{}^\circ C\]. The heat will (a) flow from iron ball to water (b) not flow from iron ball to water or from water to iron ball (c) flow from water to iron ball (d) increase the temperature of both
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• question_answer20)
   A wooden spoon is dipped in a cup of ice-cream, then its other end (a) becomes cold by the process of conduction (b) becomes cold by the process of convection (c) becomes cold by the process of radiation (d) does not become cold
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• question_answer21)
  Stainless steel pans are usually provided with copper bottoms. The reason for this could be that (a) copper bottom makes the pan more durable (b) such pan appear colourful (c) copper is a better conductor of heat than the (d) stainless steel (d) copper is easier to clean than the stainless steel
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