Executive Examiner Summary

The October 2025 International AS Physics series provided a balanced but rigorous test of students' conceptual grasp and numerical precision. Across Unit 1, 2, and 3, students faced a classic mix of mathematical derivations, multi-step kinematics, and qualitative explanations requiring highly structured arguments. Solid performance was noted in standard calculations, whereas marks were frequently lost in extended writing questions (indicated with asterisks) and in the geometry-intensive optics questions.

Where the Marks Are Won or Lost

In Unit 1, moments (Question 20) and projectile trajectory analysis (Question 19) carried substantial weight. Candidates who meticulously tracked horizontal and vertical components of velocity scored highly, whereas those who ignored the launch height of the shot put missed critical vertical kinematics marks. In Unit 2, the 16-mark photoelectric effect question was a major differentiator; students struggled with converting units (photons per second, eV to Joules) and detailing the physical mechanism of electron release. Unit 3 heavily penalized poor graphical skills, emphasizing the necessity of choosing sensible scales and plotting points to within 1 mm accuracy.

Examiner Pitfalls & Mistakes to Avoid

  • Unit Conversion Blunders: A persistent issue was failing to convert cross-sectional areas from \( \text{cm}^2 \) to \( \text{m}^2 \), or Young modulus from \( \text{GPa} \) to \( \text{Pa} \). These carry heavy consequences in materials calculations.
  • Vague Explanations of Phase: Writing that waves are 'out of phase' without specifying the exact phase difference (e.g., \( 180^\circ \) or \( \pi \) radians) prevented students from gaining full marks in wave superposition questions.
  • Moment Vector Directions: In moments questions, failing to explicitly state whether the moment was clockwise or anticlockwise relative to a defined pivot was a common error.

Preparation Strategy & Revision Priorities

To maximize ROI, students should focus intensively on potential divider mathematics and graphical analysis. Drawing scaled vector diagrams accurately using a protractor and ruler is also an easy way to secure marks that many candidates skip. Practice deriving algebraic relationships (such as proving that elastic strain energy is proportional to \( F^2 \)) as these are frequently targeted in standard examinations.