Executive Summary

The May/June 2025 Physics (9702) papers present a balanced mix of conceptual recall, algebraic manipulation, and experimental evaluation. Paper 12 continues to test quick reasoning and unit conversions, while Paper 22 features classic mechanics, waves, and circuits with several multi-step derivations that require precision. Paper 32 places a strong focus on systematic measurement techniques and evaluating uncertainties in mechanical and electrical systems.

Where Marks Were Won and Lost

In Paper 22, candidates secured high marks on direct applications of formulas, such as calculating kinetic energy and basic radioactive decay equations. However, significant marks were lost in the following areas:

  • Derivations: Showing that \( E_k = \frac{1}{2}mv^2 \) from first principles was occasionally incomplete, with candidates failing to explicitly state the constant acceleration kinematics substitution.
  • Vector Geometry: Constructing a closed, tip-to-tail vector triangle in Question 2(b) proved challenging, with many drawing separate components or ignoring the direction of the forces.
  • Prefix Errors: Calculating the cross-sectional area in the Young modulus question often suffered from power-of-ten errors, specifically when dealing with GPa (\( 10^9 \)) and extensions in mm (\( 10^{-3} \)).
  • Circuit Analysis: Explaining the zero-galvanometer condition in a bridge circuit using resistance ratios was poorly articulated, despite candidates possessing the quantitative capability.

Practical Skills (Paper 32) Pitfalls

In the practical exam, candidates struggled with the physical properties of the materials provided. In the rubber cord oscillation experiment, many failed to account for the compression of the cord by the caliper jaws, leading to inaccurate diameter measurements. Additionally, in the LDR experiment, failing to align the sensor properly within the tube introduced a systematic bias that distorted the linear relationship on the graph.

Preparation & Strategy

To excel in future papers, students must prioritize derivation practice and graphical consistency. Always state the physical principles (e.g., conservation of energy or momentum) before diving into algebraic steps. In practical revisions, practice using a micrometer screw gauge and a vernier caliper on soft or compressible items, and master the quick calculation of percentage uncertainties.