CLASS 7 NCERT HEAT

 

Worksheet1

Heat (Class 7 NCERT)

Section A: Fill in the blanks

  1. Heat flows from a _________ body to a _________ body.
  2. The SI unit of heat is _________.
  3. _________ is the measure of the hotness or coldness of a body.
  4. A _________ is used to measure temperature.
  5. The transfer of heat in liquids and gases takes place by _________.

Section B: True or False

  1. Conduction is the mode of heat transfer in solids. (____)
  2. Dark-colored objects absorb less heat compared to light-colored objects. (____)
  3. Metals are good conductors of heat. (____)
  4. The boiling point of water is 100°C at standard atmospheric pressure. (____)
  5. Heat transfer by radiation does not require any medium. (____)

Section C: Match the following

Column AColumn B
1. Convectiona. Heat transfer in solids
2. Conductionb. Heat transfer in liquids/gases
3. Radiationc. Sun's heat reaching Earth
4. Land breezed. Nighttime coastal wind
5. Sea breezee. Daytime coastal wind

Section D: Short Answer Questions

  1. Define conduction and give one example.
  2. What is the difference between heat and temperature?
  3. Explain why wearing light-colored clothes in summer is more comfortable.
  4. What is the role of thermometers in measuring temperature? Name two types of thermometers.
  5. How does heat transfer take place by radiation? Give one example.


Section E: Application-Based Questions

  1. Why do we prefer to use cooking utensils made of metals like copper or aluminum?
  2. Why are the handles of cooking utensils made of materials like wood or plastic?
  3. In winter, why does a metal chair feel colder than a wooden chair, even if both are at the same room temperature?

Worksheet 2

Heat

1. Multiple Choice Questions (MCQs)

  1. Heat flows from:                                                                                     a) A colder object to a hotter object
    b) A hotter object to a colder object
    c) Both directions equally
    d) Neither direction

  2. Which of the following is the best conductor of heat?
    a) Plastic
    b) Wood
    c) Silver
    d) Glass

  3. The unit of temperature in the SI system is:
    a) Degree Celsius
    b) Kelvin
    c) Fahrenheit
    d) Joule

  4. The method of heat transfer in solids is:
    a) Conduction
    b) Convection
    c) Radiation
    d) All of these

2. Fill in the Blanks

  1. The transfer of heat without the help of a medium is called __________.
  2. The thermometer used to measure the human body temperature is called a __________ thermometer.
  3. __________ surfaces are good reflectors of heat.
  4. The process by which heat is transferred in liquids and gases is called __________.

3. Match the Following

Column AColumn B
Conduction     Sunlight reaching Earth
Convection     Heat transfer in liquids
Radiation     Heat transfer in solids

4. True or False

  1. Dark-colored objects are good absorbers of heat.
  2. Land heats up and cools down faster than water.
  3. The normal human body temperature is 40°C.
  4. A laboratory thermometer can measure temperatures below 0°C.

5. Short Answer Questions

  1. Define conduction, convection, and radiation with examples.
  2. Why do we wear light-colored clothes in summer?
  3. What is the range of a clinical thermometer?

6. Long Answer Questions

  1. Explain the construction and working of a laboratory thermometer.
  2. Describe how heat transfer occurs when we boil water in a pan.

7. Activities

  1. Activity on Conduction: Take a metal spoon and a wooden stick. Dip both into hot water and observe which one becomes hot faster. Record your observations.
  2. Activity on Convection: Heat water in a transparent glass container. Drop some food coloring and observe the movement of water particles. Draw a diagram to show convection currents.
  3. Activity on Radiation: Place two objects, one black and one white, under sunlight for 10 minutes. Touch them and compare their temperatures.

8. HOTS (Higher Order Thinking Skills)

  1. Why are houses in hot regions painted white?
  2. Can convection occur in solids? Why or why not?
  3. If a person’s skin feels cold to the touch, what can you infer about their body heat transfer?
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