NCERT Solutions For Class 7 Science Chapter 4 – Heat

Learn from School Connect Online in this chapter we will learn about heat where heat is a form of energy which makes the substance hot. In winter, it is our common experience that we feel cold inside the house and if we come out in front of sun rays, then we feel warm. 

Download PDF of NCERT Solutions for Class 7 Science   

NCERT Solutions Download Class 7Chapter NameNCERT Solutions Download Class 7Chapter Name
NCERT Solutions For Class 7 Science Chapter 1: Nutrition In PlantsNutrition in PlantsNCERT Solutions for Class 7 Chapter 10 Respiration in OrganismsRespiration in Organisms
NCERT Solutions for Class 7 Chapter 2 Nutrition in AnimalsNutrition in AnimalsNCERT Solutions for Class 7 Chapter 11 Transportation in Animals and PlantsTransportation in Animals and Plants
NCERT Solutions for Class 7 Chapter 3 Fibre to FabricFibre to FabricNCERT Solutions for Class 7 Chapter 12 Transportation in Animals and PlantsReproduction in Plants
NCERT Solutions for Class 7 Chapter 4 HeatHeatNCERT Solutions for Class 7 Chapter 13 Motion and TimesMotion and Times
NCERT Solutions for Class 7 Chapter 5 Acids,Bases and SaltsAcids,Bases and SaltsNCERT Solutions for Class 7 Chapter 14 Electric Current and its EffectsElectric Current and its Effects
NCERT Solutions for Class 7 Chapter 6 Physical and Chemical ChangesPhysical and Chemical ChangesNCERT Solutions for Class 7 Chapter 15 LightLight
NCERT Solutions for Class 7 Chapter 7Weather,Climate and Adaptations of Animals to ClimateNCERT Solutions for Class 7 Chapter 16 Water;A precious resourceWater;A precious resource
NCERT Solutions for Class 7 Chapter 8Winds Storms and CyclonesNCERT Solutions for Class 7 Chapter 17 Forests;Our life lineForests;Our life line
NCERT Solutions for Class 7 Chapter 9SoilNCERT Solutions for Class 7 Chapter 18 Waste water storyWaste water story

Exercise Questions

1. State similarities and differences between the laboratory thermometer and the clinical thermometer.

Solution:

Similarities

  • Both are made of glass and consist of long narrow glass tube.
  • At one end both of them have a bulb.
  • Bulbs of both the thermometers consist of mercury
  • Celsius scale is present in both the thermometer

Differences

Clinical ThermometerLaboratory thermometer
Temperature range if 35 to 42 0 cTemperature range is -10 to 110 0 c
Used to measure human body temperatureUsed to measure temperature in the laboratory
It has kink which prevents immediate backflow of mercuryIt does not have a kink

2. Give two examples each of conductors and insulators of heat.

Solution:

Conductors: Iron and Copper

Insulators: Plastic and wood

3.Fill in the blanks :

(a) The hotness of an object is determined by its __________.

Sol : The hotness of an object is determined by its temperature.

(b) Temperature of boiling water cannot be measured by a _____________ thermometer.

Sol : Temperature of boiling water cannot be measured by a clinical thermometer.

(c) Temperature is measured in degree ______________.

Sol : Temperature is measured in degree Celcius.

(d) No medium is required for transfer of heat by the process of __________.

Sol : 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. Heat is transferred to its other end by the process of ______________.

Sol : A cold steel spoon is dipped in a cup of hot milk. Heat is transferred to its other end by the process of conduction.

(f ) Clothes of ______________ colours absorb more heat better than clothes of light colours.

Sol : Clothes of dark colours absorb more heat better than clothes of light colours.

4. Match the following :

Column-IColumn-II
(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

Solution:

Column-IColumn-II
(i) The land breeze blows during(d) night
(ii) The sea breeze blows during(c) day
(iii) Dark coloured clothes are preferred during(b) winter
(iv) Light coloured clothes are preferred during(a) summer
NCERT Solutions For Class 7 Science Chapter 4 Heat

5. Discuss why wearing more layers of clothing during winter keeps us warmer than wearing just one thick piece of clothing.

Solution:

More layers of clothing during winter keeps us warmer than wearing just one thick piece of clothing because air gets trapped in-between layers. As air is a bad conductor of heat it does not allow the escape of the heat from the body.

6. Look at Fig. 4.13. Mark where the heat is being transferred by conduction, by convection and by radiation.

Solution:

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

Solution:

In places of hot climate, it is advised that the outer walls of houses be painted white because white colour reflects back most of the heat that is incident on it as white is a poor absorber of heat. This helps in keeping the house cool.

8. 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

Solution:

The temperature of the mixture will be between 30°C and 50°C because hot water loses the heat and simultaneously cold water gains heat this keeps the temperature in between 30°C and 50°C.

9. 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.

Solution:

Answer is (b) not flow from iron ball to water or from water to iron ball because both of them have the same temperature of 40°C.

10. 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.

Solution:

The answer is (d) does not become cold because wood is a bad conductor of heat.

11. 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 stainless steel.

(d) copper is easier to clean than stainless steel.

Solution:

The answer is (c) copper is a better conductor of heat than the stainless steel.

CBSE Notes for Class 7 Science Free Download for All Chapters

CBSE Class 7 Science Study NotesCBSE Class 7 Science Study Notes
Nutrition in Plants Class 7 Notes Chapter 1Respiration in Organisms Class 7 Notes Chapter 10
Nutrition in Animals Class 7 Notes Chapter 2Transportation in Animals and Plants Class 7 Notes Chapter 11
Fibre to Fabric Class 7 Notes Chapter 3Reproduction in Plants Class 7 Notes Chapter 12
Heat Class 7 Notes Chapter 4Motion and Times Class 7 Notes Chapter 13
Acids,Bases and Salts Class 7 Notes Chapter 5Electric Current and its Effects Class 7 Notes Chapter 14
Physical and Chemical Changes Class 7 Notes Chapter 6Light Class 7 Notes Chapter 15
Weather,Climate and Adaptations of Animals to Climate Class 7 Notes Chapter 7Water;A precious resource Class 7 Notes Chapter 16
Winds Storms and Cyclones Class 7 Notes Chapter 8Forests;Our life line Class 7 Notes Chapter 17
Soil Class 7 Notes Chapter 9Waste water story Class 7 Notes Chapter 18

Science Olympiad

ClassSyllabusClassSyllabus
Class 9Science Olympiad Syllabus for Class 9 (Biology)Class 10Science Olympiad Syllabus for Class 10 (Chemistry)
Class 9Science Olympiad Syllabus for Class 9 (Physics)Class 10Science Olympiad Syllabus for Class 10 (Biology)
Class 9Science Olympiad Syllabus for Class 9 (Chemistry)Class 10Science Olympiad Syllabus for Class 10 (Physics)

Science Olympiad

ClassSyllabusClassSyllabus
Class 11Science Olympiad Syllabus for Class 11(Physics)Class 12Science Olympiad Syllabus for Class 12 (Chemistry)
Class 11Science Olympiad Syllabus for Class 11 (Chemistry)Class 12Science Olympiad Syllabus for Class 12 (Biology)
Class 11Science Olympiad Syllabus for Class 11 (Biology)Class 12Science Olympiad Syllabus for Class 12 (Physics)

Learn with best notes,free videos,practice questions and mock tests with School Connect Online for free demo click here

School Connect Online

By School Connect Online

School Connect Online is an Integrated Learning Program for Academic Institution,and supported and mentored by StartUp Oasis,an inititive of CIIE IIM-Ahmedabad. Please visit school.schoolconnectonline.com

Leave a Reply