Transfer Of Thermal Energy (continued)
Overview
A metal spoon left in a hot drink soon burns your fingers, warm air rises from a radiator to fill a room, and you feel the Sun's heat across empty space. These are the three ways thermal energy travels: conduction, convection and radiation. Knowing which one is at work, and often more than one at once, lets you explain almost every heating and cooling effect around you.
In this lesson you will explain everyday applications of conduction, convection and radiation, from cooking pans to heating a room. You will describe experiments that distinguish good and bad emitters and absorbers of infrared radiation, see how surface temperature and area control the rate of radiation, and explain complex cases such as a coal fire and a car radiator where more than one transfer matters.
Objectives
- [Core] Know that thermal energy transfer by thermal radiation does not require a medium and is mainly due to infrared radiation
- [Core] Describe the effect of surface colour (black or white) and texture (dull or shiny) on the emission, absorption and reflection of thermal radiation
- [Core] Identify and explain some of the basic everyday applications and consequences of conduction, convection and radiation
- [Supplement] Know that the temperature of the Earth is affected by the radiation absorbed by the Earth and the radiation emitted by the Earth
- [Supplement] Describe experiments to distinguish between good and bad emitters of thermal radiation
- [Supplement] Describe experiments to distinguish between good and bad absorbers of thermal radiation
Audio Lesson
Listen to this lesson in the app
Mind map
This topic is mapped out so you can see how the ideas connect.
Open the mind map in the app
Flashcards
Quick recall practice on the facts this topic is tested on.
Practise these cards in the app
Lesson Note
Complete Note Available on the Green Bridge App
Get the Green Bridge CBT app on your phone or computer for the complete IGCSE library: past papers, mark schemes, mind maps, flashcards and audio lessons.
Lesson Evaluation
Congratulations on completing the lesson on Transfer Of Thermal Energy (continued). Now that youve explored the key concepts and ideas, its time to put your knowledge to the test. This section offers a variety of practice questions designed to reinforce your understanding and help you gauge your grasp of the material.
You will encounter a mix of question types, including multiple-choice questions, short answer questions, and essay questions. Each question is thoughtfully crafted to assess different aspects of your knowledge and critical thinking skills.
Use this evaluation section as an opportunity to reinforce your understanding of the topic and to identify any areas where you may need additional study. Don't be discouraged by any challenges you encounter; instead, view them as opportunities for growth and improvement.
- Which method of thermal energy transfer can take place through a vacuum? A. conduction B. convection C. radiation D. none of these Answer: C
- A saucepan handle is made of plastic mainly because plastic is a A. good conductor B. good emitter C. poor conductor D. good absorber Answer: C
- Warm air rises from a heater because, when heated, the air becomes A. more dense B. less dense C. heavier D. cooler Answer: B
- Which surface is the best emitter of infrared radiation? A. shiny silver B. shiny white C. dull black D. polished metal Answer: C
- The rate at which an object emits radiation increases if its A. surface temperature falls B. surface area decreases C. surface temperature rises D. colour becomes shinier Answer: C
Work through these questions in the app
Work through these questions in the app
Recommended Books
Practice Mock Questions
Want to practice mock questions on Transfer Of Thermal Energy (continued)? Download the Green Bridge CBT app to access mock questions and full practice assessments for this topic.
Download The App On Google Playstore
Everything you need to excel in your exams
