DP Physics (first assessment 2025)
Question 21N.2.SL.TZ0.6a.ii
| Date | November 2021 | Marks available | [Maximum mark: 3] | Reference code | 21N.2.SL.TZ0.6a.ii |
| Level | SL | Paper | 2 | Time zone | TZ0 |
| Command term | Explain | Question number | a.ii | Adapted from | N/A |
a.ii.
[Maximum mark: 3]
21N.2.SL.TZ0.6a.ii
(a.ii)
Titan has an atmosphere of nitrogen. The albedo of the atmosphere is 0.22. The surface of Titan may be assumed to be a black body. Explain why the average intensity of solar radiation absorbed by the whole surface of Titan is 3.1 W m−2
[3]
Markscheme
exposed surface is ¼ of the total surface ✓
absorbed intensity = (1−0.22) × incident intensity ✓
0.78 × 0.25 × 15.7 OR 3.07 «W m−2» ✓
Allow 3.06 from rounding and 3.12 if they use 16 W m−2.
