Close Menu
    Facebook X (Twitter) Instagram
    CBSE Learning
    • Home
    • NCERT Solutions
    • Class 12
      • Class 12 Physics
      • Class 12 Chemistry
      • Class 12 Maths
      • Class 12th Biology
      • Class 12 English
      • Class 12 Accountancy
      • Class 12 Economics
      • Class 12 Business Studies
      • Class 12 Political Science
      • Class 12 Sociology
      • Class 12 Psychology
    • Class 11
      • Class 11 Maths
      • Class 11 Physics
      • Class 11 Chemistry
      • Class 11 Biology
      • Class 11 Accountancy
      • Class 11 English
      • Class 11 Economics
      • Class 11 Business Studies
      • Class 11 Political Science
      • Class 11 Psychology
      • Class 11 Sociology
    • Class 10
      • Class 10 English
      • Class 10 Maths
      • Class 10 Science
      • Class 10 Social Science
    • Class 9
      • Class 9 Maths
      • Class 9 English
      • Class 9 Science
      • Class 9 Social Science
    • Class 8
      • Class 8 Maths
      • Class 8 Science
      • Class 8 English
      • Class 8 Social Science
    • Class 7
      • Class 7 Maths
      • Class 7 Science
      • Class 7 English
      • Class 7 Social Science
    • Class 6
      • Class 6 Maths
      • Class 6 Science
      • Class 6 English
      • Class 6 Social Science
    CBSE Learning
    Home » NCERT Solutions for Class 7 Science Chapter 4 – Heat
    Class 7 Science

    NCERT Solutions for Class 7 Science Chapter 4 – Heat

    AdminBy AdminUpdated:August 8, 20235 Mins Read
    Facebook Twitter Pinterest LinkedIn Tumblr Email
    Share
    Facebook Twitter LinkedIn Pinterest Email

     

    Exercise : Solutions of Questions on Page Number : 45


    Q1 : State similarities and differences between the laboratory thermometer andthe clinical thermometer.

    Answer :
    Similarities:
    (i) Both clinical and laboratory thermometers have long, narrow, uniform glass tubes.
    (ii) The bulbs of both the thermometers have mercury in them.
    Differences:
    (i) The temperature range of clinical thermometers is from 35°C to 42°C while that of laboratory thermometer is from -10°C to 110°C.
    (ii) Clinical thermometer is used to measure the temperature of a human body. However, laboratory thermometer cannot be used to measure the temperature of a human body.
    (iii) The least count of both the thermometers differs.
    (iv) Unlike clinical thermometer that can be tilted, laboratory thermometer is kept upright while reading the temperature values.


    Q2 : Give two examples each of conductors and insulators of heat.

    Answer :
    Two examples of conductors of heat are:
    (i) Aluminium
    (ii) Iron
    Two examples of insulators of heat are:
    (i) Wood
    (ii) Plastic


    Q3 : Fill in the blanks:
    (a) The hotness of an object is determined by its __ __.
    (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 transfers heat to its other end by the process of __ _ _.
    (f) Clothes of ___ _ colours absorb heat better than clothes of light colours.

    Answer :
    a) The hotness of an object is determined by its __temperature__.
    (b) Temperature of boiling water cannot be measured by a __clinical__thermometer.
    (c) Temperature is measured in degree __Celsius__.
    (d) No medium is required for transfer of heat by the process of __radiation__.
    (e) A cold steel spoon is dipped in a cup of hot milk. It transfers heat to its other end by the process of __conduction__.
    (f) Clothes of __dark__colours absorb heat better than clothes of light colours.


    Exercise : Solutions of Questions on Page Number : 46
    Q4 : Match the following:

    (i)Land breeze blows during(a)summer
    (ii)Sea breeze blows during(b)winter
    (iii)Dark coloured clothes are preferred during(c)day
    (iv)Light coloured clothes are preferred during(d)night

    Answer:

    (i)Land breeze blows during(d)night
    (ii)Sea breeze blows during(c)day
    (iii)Dark coloured clothes are preferred during(b)winter
    (iv)Light coloured clothes are preferred during(a)summer

    Q5 : Discuss why wearing more layers of clothing during winters keeps us warmer than wearing just one thick piece of clothing.

    Answer :
    During winters, we prefer wearing more layers of clothing than just one thick piece of clothing because air gets trapped in between the various clothing layers. Being a poor conductor of heat, air prevents heat loss from our body. Hence, layers of clothing keep us warmer than a single layer.


    Q6 : Look at Figure. Mark where the heat is being transferred by conduction, by convection and by radiation.


    Answer :
    (i) Transfer of heat from burner to pan is by radiation.
    (ii) Transfer of heat from pan to water is by conduction.
    (iii) Transfer of heat within water is by convection.


    Q7 : In places of hot climate it is advised that the outer walls of houses be painted white. Explain.

    Answer :
    In places of hot climate, it is advised to paint the outer walls of houses as white because a light colour such as white reflects back most of the heat that falls on it. Hence, a light colour tends to keep the house cool.


    Q8 : One litre of water at 30°C is mixed with one litre of water at 50°C. The temperature of the mixture will be
    (a) 80°C (b) more than 50°C but less than 80°C
    (c) 20°C (d) between 30°C and 50°C

    Answer :
    (d)
    The temperature of the mixture will be between 30°C and 50°C.


    Exercise : Solutions of Questions on Page Number : 47
    Q9 : An iron ball at 40°C is dropped in a mug containing water at 40°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.

    Answer :
    (b)
    The heat will not flow from iron ball to water or from water to iron ball as both the substances have same temperature.


    Q10 : A wooden spoon is dipped in a cup of ice cream. 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.

    Answer :
    (d)
    Its other end does not become cold as wood is a bad conductor of heat.


    Q11 : 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 pans appear colourful.
    (c) copper is a better conductor of heat than the stainless steel.
    (d) copper is easier to clean than the stainless steel.

    Answer :
    (c)
    The reason for this is that copper is a better conductor of heat than stainless steel.


    Share. Facebook Twitter Pinterest LinkedIn Tumblr Email
    Previous ArticleNCERT Solutions for Class 7 Science Chapter 3 – Fibre to Fabric 
    Next Article NCERT Solutions for Class 7 Science Chapter 5 – Acids, Bases and Salts 
    Recent Posts
    • How many states and union territories are in India
    NCERT Book Solutions
    • NCERT Solutions for Class 12 Maths
    • NCERT Solutions for Class 12 Physics
    • NCERT Solutions for Class 12 Chemistry
    • NCERT Solutions for Class 12 Biology
    • NCERT Solution for Class 11 – Physics
    • NCERT Solutions for Class 11 Chemistry
    • NCERT Solutions for Class 11 Maths
    • NCERT Solutions for Class 11 Biology
    • NCERT Solutions for Class 11 – Accountancy
    • NCERT Solutions for Class 11 – English
    • NCERT Solutions for Class 10 Maths – 2023 Updated
    • NCERT Solutions for Class 10 Science
    • NCERT Solutions for Class 10 – English
    • NCERT Solutions for Class 9 Maths 2023
    • NCERT Solutions for Class 9 – Science
    Exams
    • Privacy Policy
    • NEET 2024
    • NCERT Solutions for Class 8 Sanskrit
    Links
    Latest News
    Contact Us
    Privacy Policy
    Ask a Doubt
    © 2023 CBSE Learning

    Type above and press Enter to search. Press Esc to cancel.