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Chapter Analysis
Beginner15 pages • EnglishQuick Summary
The chapter 'Heat' for Class 7 Science introduces the concept of heat and its transfer through conduction, convection, and radiation. It explains how materials can be classified as conductors or insulators based on their ability to transfer heat. The chapter also discusses the use of thermometers and the temperature scales, as well as the reasons why we wear different types of clothes in summer and winter based on their properties of absorbing or reflecting heat.
Key Topics
- •Conduction
- •Convection
- •Radiation
- •Conductors and Insulators
- •Thermometers and Temperature Scales
- •Clothing and Heat Absorption
- •Sea Breeze and Land Breeze
Learning Objectives
- ✓Understand different modes of heat transfer: conduction, convection, and radiation.
- ✓Identify materials as conductors or insulators of heat.
- ✓Learn how to measure temperature using different types of thermometers.
- ✓Appreciate the role of clothing in regulating body temperature.
- ✓Explore the natural phenomena of land and sea breezes.
Questions in Chapter
State similarities and differences between the laboratory thermometer and the clinical thermometer.
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Give two examples each of conductors and insulators of heat.
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Fill in the blanks: The hotness of an object is determined by its __________.
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Match the following: Land breeze blows during
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Discuss why wearing more layers of clothing during winter keeps us warmer than wearing just one thick piece of clothing.
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Additional Practice Questions
Explain the process of conduction with an example.
mediumAnswer: Conduction is the transfer of heat through direct contact. For instance, when a metal rod is heated at one end, the heat travels to the other end. Metals are good conductors as they facilitate this transfer.
What is radiation and how is it different from conduction and convection?
mediumAnswer: Radiation is the transfer of heat through electromagnetic waves without the need for a medium. Unlike conduction and convection, it can occur in a vacuum. An example is the heat from the sun reaching the Earth.
Why is it advised to wear white clothes in summer?
easyAnswer: White clothes are advised in summer because they reflect most of the heat falling on them, keeping the body cooler compared to dark-colored clothes which absorb more heat.
Discuss land and sea breezes with diagrams.
hardAnswer: Land breeze occurs at night when the land cools faster, causing cooler air to move towards the sea, while sea breeze occurs during the day when land heats up faster, drawing cooler air from the sea. Diagrams show air circulation patterns.
How do thermometers measure temperature, and why can't we use a clinical thermometer to measure the temperature of boiling water?
mediumAnswer: Thermometers measure temperature using thermal expansion of a liquid, like mercury, that ascends with rising temperature. Clinical thermometers are limited to a range of 35°C to 42°C, unsuitable for high temperatures like boiling water.
NCERT Exemplar
AvailablePractice with NCERT Exemplar problems and solutions for this chapter. Exemplar problems are designed to help you master the concepts with advanced-level questions.
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