DP Physics (first assessment 2025)
Question 19M.2.SL.TZ1.b
| Date | May 2019 | Marks available | [Maximum mark: 1] | Reference code | 19M.2.SL.TZ1.b |
| Level | SL | Paper | 2 | Time zone | TZ1 |
| Command term | Outline | Question number | b | Adapted from | N/A |
b.
[Maximum mark: 1]
19M.2.SL.TZ1.b
The albedo of the Earth’s atmosphere is 0.28. Outline why the maximum temperature of a black body on the Earth when the Sun is overhead is less than that at point A on the Moon.
[1]
Markscheme
(28 %) of sun’s energy is scattered/reflected by earth’s atmosphere OR only 72 % of incident energy gets absorbed by blackbody ✔
Must be clear that the energy is being scattered by the atmosphere.
Award [0] for simple definition of “albedo”.
Examiners report
This question was assessing the understanding of the concept of albedo. Many candidates were able to connect that an albedo of 0.28 meant that 28 % of the incident energy from the sun was being reflected or scattered by the atmosphere before reaching the black body.
