2026 Cambridge IAS-Level Physics (9702) Past Paper: Analysis & Answers

Overall Verdict & Exam Character

The May/June 2026 series for AS Level Physics (9702) represents a balanced and conceptually rigorous assessment. The structured paper (Paper 23) placed significant emphasis on multistep physical explanations and graphical interpretation, particularly in two-body collisions, non-uniform stress distribution in hanging polythene threads, and physical models of wave interference. Paper 13 sustained standard AS multiple-choice rigour, demanding swift algebraic manipulation and firm conceptual grasp of core phenomena. Practical Paper 33 balanced traditional timing oscillations with an unconventional geometric stability and toppling experiment.

Distribution of Marks & Key Themes

Across the written and practical components, marks are distributed strategically across core domains:

• Mechanics & Dynamics: Strong focus on momentum conservation, relative speed of approach and separation in elastic collisions, and kinematic graph analysis (Paper 23 Q1).
• Deformation of Solids: In-depth analytical testing on the variation of tension and stress along a vertical hanging thread under its own weight, connecting Hookean elasticity to elastic strain energy (Paper 23 Q2).
• Superposition & Wave Optics: Explicit descriptive requirements on phase difference, path difference, and coherent superposition, combined with double-slit fringe geometry \( \lambda = \frac{ax}{D} \) (Paper 23 Q3).
• D.C. Circuits & Practical Measurement: Practical potential dividers featuring LDRs, terminal potential difference, and internal resistance \( E = V + Ir \), coupled with experimental error evaluation (Paper 23 Q4, Paper 33).
• Particle & Nuclear Physics: Standard quark model classifications, \( \beta^+ \) decay balance, and the thermodynamic rationale behind continuous beta energy spectra due to neutrino sharing (Paper 23 Q5).

Examiner Traps & Common Candidate Pitfalls

Mark schemes highlight recurring areas where marks were unnecessarily dropped:

• Imprecise Definitions: Stating momentum as 'mass times speed' instead of velocity, or Young modulus as 'stiffness' rather than stress divided by strain.
• Kinematic Displacements vs. Distance: In collision velocity-time graphs, confusing negative displacement area with scalar distance traversed during deceleration.
• Relative Speed vs. Relative Velocity: Conflating the sign conventions in the elastic collision condition \( u_1 - u_2 = v_2 - v_1 \).
• Explanations of Maxima/Minima: Omitting explicit reference to waves arriving 'in phase' with zero path difference when justifying central bright fringe formation.
• Practical Limitations: Giving vague responses like 'human error' or 'ruler inaccurate' instead of specifying difficulty in judging the instant of toppling or parallax in protractor alignment.

Preparation & Exam Strategy

To maximize scores in future sittings, students should:

• Consistently memorize standard Cambridge definitions word-for-word using vector terminology where required.
• Master area-under-the-graph principles, paying careful attention to sign conventions and directional reversals.
• Practice structured three-point explanations for wave interference: state meeting of waves, phase/path difference, and resultant constructive/destructive superposition.
• In Paper 3, record all raw measurements to the precise resolution of the instrument (e.g., nearest mm on a metre rule, nearest degree on a protractor) and quote gradient and intercept with complete physical units.