The table shows how a sheet interacts with two wavelengths of radiation.
| Wavelength | Energy incident | Energy transmitted | Energy reflected |
|---|---|---|---|
| 450 nm450\ \mathrm{nm}450 nm | 100 J | 60 J | 25 J |
| 900 nm900\ \mathrm{nm}900 nm | 200 J | 40 J | 80 J |
Which statement about the percentage of energy absorbed is correct?
It is greater at 450 nm450\ \mathrm{nm}450 nm: 40%40\%40% compared with 20%20\%20%.
It is greater at 900 nm900\ \mathrm{nm}900 nm: 60%60\%60% compared with 25%25\%25%.
It is greater at 900 nm900\ \mathrm{nm}900 nm: 40%40\%40% compared with 15%15\%15%.
It is greater at 450 nm450\ \mathrm{nm}450 nm: 75%75\%75% compared with 60%60\%60%.
84 exam-style questions on Edexcel GCSE Physics 5.2 The electromagnetic spectrum, covering 5.2.1 Electromagnetic waves and refraction in glass (core practical), 5.2.2 Groups of the electromagnetic spectrum, 5.2.3 Wavelength-dependent behaviour of EM waves, and 5.2.4 Velocities of EM waves in different substances. Each one has a worked solution and a mark scheme showing where the marks go.