During a quality-control review, a technician examines test records for two metal casings that are identical except for their surface finish. An infrared detector viewed the same area of each casing from the same distance and angle.
| Surface finish | Surface temperature when tested (°C) | Detector reading (mV) |
|---|---|---|
| Matt black | 50 | 0.38 |
| Shiny silver | 80 | 0.52 |
The technician concludes that shiny silver is a better emitter of infrared radiation than matt black.
Evaluate whether the records support the technician's conclusion. Suggest one change that would allow a fair comparison. State which casing should then give the greater detector reading.
93 exam-style questions on AQA GCSE Physics 6.2 Electromagnetic waves, covering 6.2.1 Types of electromagnetic waves, 6.2.2 Properties of electromagnetic waves 1, 6.2.3 Properties of electromagnetic waves 2, 6.2.4 Uses and applications of electromagnetic waves, 6.2.5 Lenses, and 6.2.6 Visible light. Each one has a worked solution and a mark scheme showing where the marks go.