Cambridge IGCSE Physics Notes 2.3: Transfer of Thermal Energy
Cambridge IGCSE Physics notes on conduction, convection, infrared radiation, emitters, absorbers, insulation, and thermal-transfer consequences.
Q: What does Cambridge IGCSE Physics Notes 2.3: Transfer of Thermal Energy cover?
A: It follows official Cambridge Physics section 2.3 for syllabuses 0625 and 0972, with Core ideas separated from Supplement depth.
Thermal energy moves by conduction, convection, and radiation. The dominant pathway depends on material, particle mobility, temperature difference, and surface properties.
The ideas that organise this section
- Conduction transfers energy through particle interactions and, in metals, mobile electrons.
- Convection requires bulk movement of a fluid caused by density differences.
- Infrared radiation needs no medium and is affected by surface colour and texture.
Core route
Core candidates should be ready to describe, calculate, interpret, and apply the following:
- Describe conduction, convection, and infrared radiation and identify them in familiar situations.
- Compare good and poor conductors and relate them to uses.
- Explain insulation choices in buildings, clothing, and containers.
Supplement route
Extended candidates study all Core content and add the following depth:
- Explain metallic conduction using free electrons.
- Relate emission and absorption rates to dull black and shiny light surfaces.
- Analyse systems in which several transfer pathways act simultaneously.
Formula route
This section is mainly qualitative. Use precise definitions, labelled diagrams, and cause-and-effect explanations.
Write the relationship before substituting. Convert units first, keep extra figures during working, and round only the final answer to sensible precision.
Build a connected model
In Transfer of Thermal Energy, a strong answer connects the named quantity or model to observable evidence. Begin by defining the physical quantity in words or with its relationship. Identify which values are scalars and which require a direction. Represent the situation with a labelled diagram, graph, field pattern, ray or circuit when that makes the relationship visible. The representation is part of the reasoning: its labels, arrows and scale should agree with the written explanation.
For a calculation, write the governing relationship before substitution, convert prefixes and time units, keep unrounded values during working and attach the correct final unit. For a qualitative question, use a cause-link-consequence chain. Name what changes, state the physical mechanism that links the change to the system, and then give the measurable result. If two cases are compared, hold unrelated variables constant and use the same physical principle for both.
