IGCSE · 2 · multiple choice
Thermal physics · Question 6
Thermal physics · Original GioPhysics question with a detailed, mark-by-mark answer guide.
- Demand
- routine
- Marks
- 1
- Topics
- 1
- Answer
- Complete
multiple choice1 mark
Four identical cans are filled with water at 80 °C and left to cool in the same room. Which can cools fastest?
- A
a can with a shiny silver surface
- B
a can with a shiny white surface
- C
a can with a dull black surface
- D
all four cool at the same rate
Ready to self-mark?Reveal the detailed answer guide
Answer overviewCorrect answer: C — a can with a dull black surface
01
1 markAnswer and reasoning
How to approach it
Predict from the governing principle before looking for a matching option. Then reject alternatives by checking direction, units, limiting behaviour or the physical meaning of each statement.
- 1
The correct choice is C: a can with a dull black surface
- 2
D tempts candidates who remember that the water and temperature are identical but forget that the surface controls the rate of emission. A dull black surface is the best emitter as well as the best absorber.
Private on this device