October 2025 Examination Verdict

The October 2025 Edexcel International AS Level Physics papers represented a balanced but challenging series. Unit 1 demanded high quantitative rigor, particularly in complex fluid-dynamics scenarios, while Unit 2 presented several long-structured explanations that tested deep conceptual understanding. Unit 3 successfully integrated standard experimental setups with rigorous mathematical rearrangement and graphical analysis.

Where the Marks Were Won and Lost

Many students excelled at standard numeric applications, such as projectile range calculations, basic moments equations, and simple series/parallel resistance calculations. However, significant marks were lost in descriptive questions requiring rigorous physical reasoning. Specifically, in Unit 1, the asterisked Quality of Written Communication (QWC) question on terminal velocity (Q14) suffered from a lack of systematic step-by-step force analysis. In Unit 2, explaining the photoelectric/photon model of light via toy stones (Q15) saw students failing to contrast the photon model explicitly with the continuous nature of wave energy transfer.

Key Examiner Pitfalls

  • Newton's Third Law in Fluids: In Unit 1 Q19, candidates struggled to recognize that the upthrust acting upward on the submerged sphere is accompanied by an equal and opposite downward force on the liquid, which is registered as an increased reading on the balance.
  • Structural Support Scaling: In Unit 2 Q17, many failed to scale the weight of the bridge road down by a factor of 500 when evaluating the tension supported by a single suspending cable, resulting in an incorrect wave speed \( v = \sqrt{T/\mu} \).
  • Graph Rearrangement: In Unit 3 Q4, setting up the LED activation potential equation in the form of \( y = mx + c \) to prove a straight-line plot was frequently missed or incorrectly grouped.

Strategic Advice & Next-Step Predictions

To maximize scores in future sessions, candidates must practice structural explanations with defined logic steps—especially for projectile components, stationary wave formations, and the particle model of light. For the upcoming series, expect a stronger focus on the de Broglie wavelength and Hooke's law limits, which were relatively light in this session. Re-visiting practical skills on percentage uncertainty calculations for composite quantities (such as density) will remain crucial for Unit 3 success.