DP Physics (last assessment 2024)
Question 19M.3.HL.TZ1.20b.ii
| Date | May 2019 | Marks available | [Maximum mark: 2] | Reference code | 19M.3.HL.TZ1.20b.ii |
| Level | HL | Paper | 3 | Time zone | TZ1 |
| Command term | Compare and contrast | Question number | b.ii | Adapted from | N/A |
b.ii.
[Maximum mark: 2]
19M.3.HL.TZ1.20b.ii
The graph shows the variation with time of the cosmic scale factor R of the universe for the flat model of the universe without dark energy.
(b.ii)
Compare and contrast, the variation with time of the temperature of the cosmic background (CMB) radiation, for the two models from the present time onward.
[2]
Markscheme
«since T ∝ » the temperature drops for both models ✔
but in the accelerating model R increases faster and so the temperature drops faster ✔
Examiners report
In (ii) however, many candidates did not directly answer the question, making little to no reference of temperature.
