A hollow metal cube is filled with boiling water. Side P of the cube is opposite Side Q. One of these two sides is painted matte black and the other is polished silver. A thermal radiation sensor is placed 10 cm from Side P, and then the same sensor is placed 10 cm from Side Q. The sensor detects a much higher rate of thermal radiation when facing Side P than when facing Side Q.
Which row in the table correctly identifies the matte black side and compares the rate of emission of thermal radiation from each side?
| Matte black side | Rate of emission of thermal radiation | |
|---|---|---|
| A | P | greater for P |
| B | P | the same for P and Q |
| C | Q | greater for Q |
| D | Q | the same for P and Q |
Matte black side: P; rate of emission of thermal radiation: greater for P
Matte black side: P; rate of emission of thermal radiation: the same for P and Q
Matte black side: Q; rate of emission of thermal radiation: greater for Q
Matte black side: Q; rate of emission of thermal radiation: the same for P and Q
301 exam-style questions on CIE IGCSE Physics 2.3 Transfer of thermal energy, covering 2.3.1a Thermal conductors and thermal insulators, 2.3.1b Explaining thermal conduction, 2.3.2 Convection, 2.3.3a Thermal radiation, 2.3.3b Surface colour and texture, 2.3.3c Rate of emission and absorption of radiation, and 2.3.4 Consequences of thermal energy transfer. Each one has a worked solution and a mark scheme showing where the marks go.