DP Physics (first assessment 2025)
Question EXE.2.SL.TZ0.5
| Date | Example questions Example questions | Marks available | [Maximum mark: 6] | Reference code | EXE.2.SL.TZ0.5 |
| Level | SL | Paper | 2 | Time zone | TZ0 |
| Command term | Discuss, Suggest | Question number | 5 | Adapted from | N/A |
5.
[Maximum mark: 6]
EXE.2.SL.TZ0.5
The ends of a vertical column of water are maintained at different temperatures Tt and Tb both above the freezing point.
Energy transfer by radiation in this arrangement is negligible.
(a)
Discuss the mechanism that accounts for the greatest rate of energy transfer when:
(a.i)
Tt > Tb
[2]
Markscheme
Conduction identified ✓
energy transfer through interaction of particles in liquid at atomic scale ✓
(a.ii)
Tb > Tt
[2]
Markscheme
Convection identified ✓
energy transfer through movement of bodies of liquid at different densities ✓
(b)
The liquid now freezes so that the vertical column is entirely of ice. Suggest how your answer to (a)(ii) will change.
[2]
Markscheme
the solid cannot now move relative to material above it ✓
so conduction only ✓