Cambridge examiner reports are publicly available but almost nobody reads them. Each one contains a detailed post-mortem of what went wrong — not just what the correct answer was, but the exact phrasing that earned marks and the exact phrasing that didn't. Reading across five years of reports for 0625 produces a short, stable list. The same mistakes appear every series.
These ten are the ones examiners flag most consistently. For each one, there's a before-and-after so you can see exactly what to write differently.
Missing or wrong units on a numerical answer
Examiners award the unit mark separately from the value. A correct calculation with no unit, or the wrong unit, loses that mark. This is one of the most cited issues in every report — it costs marks even when the physics is right.
Habit: write the unit as you write the number — not as an afterthought.
Explaining what happens instead of why it happens
Questions that ask "explain" or "state and explain" require a causal chain. Describing the outcome without linking it to a physical reason scores partial marks at best. Examiners consistently note that students "describe the effect but give no explanation."
Vague comparative language — "bigger", "more", "faster"
Examiner reports repeatedly flag answers that use non-specific comparisons. "The force is bigger" scores nothing. The mark scheme requires the physical quantity and its direction of change. Always name the quantity.
Definitions missing "per unit" language
Cambridge Physics definitions are precise constructions. Many require "per unit" phrasing that students routinely drop. Voltage, pressure, density, and speed of a wave all have definitions where missing this wording loses the mark outright.
The 0625 Definitions & Formulae flashcard trainer drills these exact phrasings.
Confusing "directly proportional" with "increases"
If a question asks about the relationship between two variables, "increases" and "directly proportional" are not interchangeable. Directly proportional means the ratio is constant and the graph passes through the origin. Many students write "increases" when the mark scheme specifically requires "directly proportional."
Confusing current through and voltage across in circuits
Examiners note this in nearly every electricity-related report. Current flows through a component; voltage exists across it. Writing "the voltage through the resistor" or "the current across the lamp" doesn't score — and it signals to the examiner that the concept isn't understood.
Waves: confusing the effects of amplitude and frequency
In sound and light, amplitude controls loudness/brightness and frequency controls pitch/colour. Examiners flag persistent confusion, particularly students writing that "a louder sound has a higher frequency" or describing a louder sound as having more waves per second. These are separate, independent properties.
Practical: wrong number of significant figures for measurements
In Paper 5, marks are lost for recording measurements to the wrong number of significant figures. A ruler reading should be given to the nearest mm (e.g. 23.5 cm, not 23 cm or 23.50 cm). A stopwatch reading should match the precision of the instrument. Examiners state this is consistently penalised.
The Paper 5 Examiner Guide covers all significant-figures rules for practical work.
Practical: not identifying the control variable
When asked to plan an experiment, students must name the independent variable (what they change), the dependent variable (what they measure), and at least one control variable (what they keep constant). Examiners note that the control variable is the most-missed element — students describe what they change and measure but forget what must stay the same.
Drawing the line of best fit incorrectly on a graph
Examiners cite two persistent graph errors: (1) joining points dot-to-dot instead of drawing a smooth best-fit line, and (2) forcing the line through the origin when the data doesn't support it. The line of best fit should minimise the total distance of points from the line — it doesn't have to pass through any specific point unless the relationship demands it.
Practise the Paper 5 skills that lose most marks
The examiner guide covers all ten of these in the context of practical questions — with ranked mistake frequencies and a 50-point self-audit.