The Most Common IGCSE Physics Exam Mistakes

Examiner reports for IGCSE Physics 0625 repeat the same complaints every session. The marks students lose most often are not on the hardest physics. They sit in predictable, fixable habits. Here are eleven of the most common mistakes, organised by paper, each with its fix. Eliminating even half of them is typically worth a grade.

What mistakes cost marks on the multiple choice papers (Paper 1 and 2)?

1. Answering from memory instead of working the question. MCQ distractors are built from the most common wrong methods. If a question needs a calculation, the wrong answers usually include the result of dividing instead of multiplying, or forgetting to square. Fix: do every numerical MCQ on paper, in the margin, exactly as you would on Paper 4. The 45 minutes allow it.

2. Misreading the stem’s “not”, “decreases” or “smallest”. Cambridge regularly asks which statement is not correct, or which value is smallest. Students solve correctly and tick the opposite. Fix: circle the operative word in the stem before reading the options. It takes two seconds.

3. Burning time on one hard question. Forty questions in 45 minutes is roughly a minute each. Three minutes on question 7 steals working time from three later questions you could answer easily. Fix: one pass at speed, flag and skip anything that stalls you, second pass for the flags. Never leave a blank, because there is no penalty for guessing.

What mistakes cost marks on the theory papers (Paper 3 and 4)?

4. No unit, or the wrong unit, on the answer line. The single most reported error. A correct 58.8 with no N often scores the method mark only. Worse is a mixed-unit substitution: grams into $F = ma$, or cm into a density formula expecting m³. Fix: convert all quantities to SI units before substituting, and write the unit as part of the answer, not as an afterthought. Also check which g the paper gives: 0625 standardises on $9.8\ \text{N/kg}$, but some questions use $10\ \text{N/kg}$; use the value printed.

5. Working invisible to the examiner. Mark schemes award M1 for a correct substituted equation. Students who do everything on the calculator and write only the final number lose every method mark the moment the answer is wrong. Fix: three written lines minimum, namely equation in symbols, equation with numbers, answer with unit.

6. Describing when the question says explain. “The pressure increases because the gas is hotter” restates the question. The explain marks sit in the mechanism: faster molecules, more frequent and harder wall collisions. Fix: every explain answer must contain a cause-to-effect chain with “so” or “because” linking physics to outcome. Our command words guide breaks down all seven.

7. Vague language where the scheme demands precise terms. “Heat rises” scores nothing; “the heated, less dense air rises and is replaced by cooler, denser air” scores. “Energy is lost” scores nothing; “energy is transferred to the surroundings by heating” scores. Fix: learn the scheme-approved phrasings for the big four (convection, conduction, induction, and energy transfer) as fixed sentences.

8. Throwing everything at the 6-mark question. Extended response questions are marked point by point: examiners reward a logical, relevant sequence, not a brain dump. Contradictions cancel correct points. Fix: plan four to six points in the margin first, order them cause-to-effect, then write. One accurate linked paragraph beats ten scattered facts.

What mistakes cost marks on the practical papers (Paper 5 and 6)?

9. Graph axes without labels, units or sensible scales. The graph question carries 4 to 5 marks, awarded line by line: labelled axes with units, a scale using 1, 2 or 5-based intervals covering more than half the grid, points plotted to within half a small square, and a thin best-fit line. Scales of 3 make plotting errors near-certain. Fix: memorise the checklist (label, unit, scale, plot, line) and run it on every graph. And never force the line through the origin unless the points go there.

10. Quoting raw readings to impossible precision, or to too little. Recording a length as 50 cm when a rule reads to 1 mm loses the precision mark; so does claiming 50.234 cm. Repeated timings recorded without averaging lose the processing mark. Fix: record to the instrument’s resolution (a metre rule to 0.1 cm, a stopwatch to 0.1 s realistically), repeat, and show the average. Time 20 oscillations and divide by 20 rather than timing one.

11. Generic answers to “suggest an improvement” questions. “Be more careful” and “repeat the experiment” score nothing on their own. The scheme wants a named source of error matched to a specific remedy. Fix: use the pairing pattern of error, then remedy: “reaction-time error starting the stopwatch, so use more oscillations” or “parallax error reading the rule, so view the scale at eye level / use a set square”. Build a bank of five such pairs; they cover most Paper 6 improvement questions.

How do you actually remove these mistakes?

Knowing the list is not the same as fixing it. Habits change through marked repetition. Take your last three attempted past papers and audit every dropped mark against the eleven items above. Most students find that seven or more marks per paper trace back to this page, not to missing physics knowledge. That is a full grade boundary’s worth across the three components.

Then attack your top three offenders one at a time. Write the fix as a rule on a card, keep it visible during your next timed paper, and re-audit. One mistake category usually dies per week of deliberate practice. In our 1-to-1 online classes, tutors keep a running error log for each student and open every 1.5-hour lesson by retesting last week’s mistake category, because a fix only counts when it survives exam pressure.

The final safeguard is a checking routine. Reserve the last five minutes of every paper for a fixed sweep: units on every answer line, the operative word in every MCQ stem, and the graph checklist on Paper 6. Students who check against a list catch slips; students who “read through” catch almost nothing. If you want an experienced eye on your own error pattern first, the free 1-hour trial lesson includes exactly this audit on a recent paper you have done.

Eleven mistakes, eleven fixes. None of them requires learning new physics, which is exactly why they are the fastest marks you will ever recover.