CBSE NCERT Solutions for Class 7 Science Chapter 4

CBSE NCERT Solutions for Class 7 Science Chapter 4  Heat (अध्याय 4 ऊष्मा) free to download in PDF or View online based on new session NCERT Books for the academic session 2019 – 2020.


CBSE NCERT Solutions for Class 7 Science Chapter 4

Heat: Question – Answers

7 Science Chapter 4: Heat

CBSE NCERT Solutions for Class 7 Science Chapter 4 Heat is given below to use online. Download links are given at the Top of the page. Visit to Class 7 Science main page.

CBSE NCERT Solutions for Class 7 Science Chapter 4 Heat




CBSE NCERT Solutions for Class 7 Science Chapter 4 in PDF download
7 Science ch 4 answers



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Important Questions with Answers
  1. Paheli and Boojho measured their body temperature. Paheli found her’s to be 98.6 °F and Boojho recorded 37°C. Which of the followng statement is true?
    (a) Paheli has a higher body temperature than Boojho.
    (b) Paheli has a lower body temperature than Boojho.
    (c) Both have normal body temperature.
    (d) Both are suffering from fever.
  2. A beggar wrapped himself with a few layers of newspaper on a cold winter night. This helped him to keep himself warm because
    (a) friction between the layers of newspaper produces heat.
    (b) air trapped between the layers of newspaper is a bad conductor of heat.
    (c) newspaper is a conductor of heat.
    (d) newspaper is at a higher temperature than the temperature of the surrounding.
  3. A marble tile would feel cold as compared to a wooden tile on a winter morning, because the marble tile
    (a) is a better conductor of heat than the wooden tile.
    (b) is polished while wooden tile is not polished.
    (c) reflects more heat than wooden tile.
    (d) is a poor conductor of heat than the wooden tile.
  4. Shopkeepers selling ice blocks usually cover them with jute sacks. Explain why.
  5. Why is it advised not to hold the thermometer by its bulb while reading it?
  6. To keep her soup warm Paheli wrapped the container in which it was kept with a woollen cloth. Can she apply the same method to keep a glass of cold drink cool? Give reason for your answer.
  7. You may have noticed that a few sharp jerks are given to clinical thermometer before using it. Why is it done so?
  8. In a mercury thermometer, the level of mercury rises when its bulb comes in contact with a hot object. What is the reason for this rise in the level of mercury?



Answers
  • 1 (c)
  • 2 (b)
  • 3 (a)
  • 4. They must use some insulating material like, sack, saw dust, newspaper, etc. to cover the ice.
  • 5. If we hold a thermometer by its bulb, the mercury in the bulb will expand due to our body temperature.
  • 6. Yes. Wool is poor conductor of heat.
  • 7. The jerk to the thermometer will allow the mercury in or above the kink to flow into the bulb so that the mercury level is below normal temperature.
  • 8. Mercury expands when heated. Hence, it rises in the capillary tube.

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