Free Transfer of thermal energy questions for IGCSE Physics (0625), part of Thermal physics. Each question has the answer and the marking points an examiner would look for.
Generate a full Transfer of Thermal Energy worksheet →All Thermal physics questionsTwo identical metal cans are painted, one dull black and one shiny silver. First, both are filled with hot water and left to cool in a dark room. Later, both are filled with cold water and left in strong sunlight.
Which can changes temperature faster in each case?
| cooling in the dark | warming in sunlight | |
|---|---|---|
| A | dull black | shiny silver |
| B | shiny silver | shiny silver |
| C | dull black | dull black |
| D | shiny silver | dull black |
Answer: C
A cup of tea cools quickly when it is first made and more slowly later.
What is the reason for this?
Answer: D
Which surface is the best emitter of infrared radiation?
Answer: A
Explain why metals are better thermal conductors than non-metals. Your answer should refer to the particles involved.
Explain.
| Part | Answer and marking points | Marks |
|---|---|---|
| free electrons as well as lattice vibrations in all solids, energy is passed on as vibrating particles (atoms) collide with neighbours B1 metals also contain free (delocalised) electrons B1 free electrons gain kinetic energy at the hot end B1 they move quickly through the metal and transfer energy to particles at the cooler end B1 | 4 |
This question is about the transfer of thermal energy in a house.
Explain, in terms of particles, how thermal energy is conducted through a brick wall.
Explain why metals are much better thermal conductors than brick.
A heater is placed near the floor. Explain how a convection current warms the whole room.
Explain why a dull black roof gets hotter in sunlight than a shiny white roof, and why it also cools faster at night.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | particles vibrate more and pass vibrations to neighbours particles at the hot side vibrate more B1 and pass on the vibrations / energy to neighbouring particles B1 | 2 |
| (b) | metals have delocalised (free) electrons that carry energy quickly metals contain free / delocalised electrons B1 which move quickly and transfer energy through the metal B1 | 2 |
| (c) | air near heater warms, expands, less dense, rises; cooler denser air sinks to replace it air near the heater is heated and expands B1 it becomes less dense and rises B1 cooler, denser air sinks to take its place, setting up a convection current B1 | 3 |
| (d) | black is a better absorber of infrared; and a better emitter dull black surfaces are better absorbers of infrared radiation B1 so the black roof heats up more in sunlight B1 it is also a better emitter so it radiates energy faster at night B1 | 3 |
The Earth absorbs thermal radiation from the Sun and emits thermal radiation into space.
State what happens to the average temperature of an object that absorbs radiation at a greater rate than it emits radiation.
The Earth’s average temperature is constant over a short period. State what this tells you about the rates of absorbing and emitting radiation.
Suggest two factors that affect the rate at which an object emits thermal radiation.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | temperature increases its temperature rises B1 | 1 |
| (b) | they are equal the rate of absorption equals the rate of emission B1 | 1 |
| (c) | surface temperature; surface colour/texture; surface area Any 2 of: surface temperature; surface colour and texture (dull black vs shiny white); surface area B2 | 2 |
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Meet Riyaz →Original Cambridge-style practice questions written for mentorriyaz.in. These are not Cambridge past paper questions, and this site is not affiliated with or endorsed by Cambridge University Press & Assessment. Updated 2026-11-04. Paper generator · mentorriyaz.in