Mark-by-Mark · Cambridge IGCSE Physics 0625

0625/62 May/Jun 2025: where students lost marks

The 4 questions the June 2025 examiners' report flagged on this paper. Full question, mark scheme, free. No sign-in needed.

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Question 1(c)(d)

5 marks · Physical quantities and measurement techniques

The question

Where students lost marks

Graph plotting was reasonable, but many lost credit for awkward scales such as 3 or 7, for scales that left the points covering less than half of the grid, and for forcing the best-fit line through the origin. For the gradient, a large triangle gave the best values, but many showed nothing on the graph to say how they got it, even though the question asked.

The trap: Scale in 1, 2 or 5s, use over half the grid, never force the line through (0, 0), and draw your gradient triangle on the graph.

Source: Paper 0625/62 (Alternative to Practical), Question 1(c)(d), June 2025 examiners' report (paraphrased)

Mark scheme, mark by mark

B1axes labelled with quantity and unit

B1suitable scales, points over at least half the grid

B1plots to half a small square

B1thin best-fit line, good judgement

B1(d) working shown on the graph and gradient = Δy/Δx

Teacher's note: The data (3.4, 11) to (13.6, 47) gives G ≈ 3.5, and its line meets the V-axis near −1, not 0. Forcing it through the origin changes the gradient and the answer.

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Question 2(b)(c)

3 marks · Electrical quantities

The question

Where students lost marks

Most read the voltmeter correctly as 0.8 V; a common misreading was 1.2 V. Most calculated the current correctly from the equation given, but common errors were rounding a correct value back to one significant figure and leaving out the unit.

The trap: 0.80 ÷ 470 = 1.7 × 10⁻³ A. Two significant figures, and the unit is half the marks.

Source: Paper 0625/62 (Alternative to Practical), Question 2(b)(c), June 2025 examiners' report (paraphrased)

Mark scheme, mark by mark

B1(b)(ii) 0.8(0) V

B1(c) I = 0.0017 or 1.7 × 10⁻³

B1(c) A / amps

Teacher's note: 0.002 A is 1 s.f. and throws away the precision of the reading. The unit is a separate mark: a perfect number without A loses it.

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Question 3(e)(f)

4 marks · Light

The question

Where students lost marks

Many could show whether f1 and f2 were equal within the limits of experimental accuracy (within 10%); the clearest way was the ratio of the smaller to the larger value, equal if it is 0.9 or more. Few chose a focusing technique that suits this experiment: with the object-to-screen distance fixed, the only acceptable answer was to move the lens slowly, backwards and forwards. Only the strongest explained the darkened room: better contrast, sharper edges.

The trap: Equal within 10%? Smaller ÷ larger ≥ 0.9. And here, focus by moving the LENS: the screen is fixed.

Source: Paper 0625/62 (Alternative to Practical), Question 3(e)(f), June 2025 examiners' report (paraphrased)

Mark scheme, mark by mark

B1(e) statement matching the results (expect yes)

B1(e) values used in a calculation to justify it

B1(f)(i) move the lens slowly / backwards and forwards

B1(f)(ii) better contrast / sharper, more visible image

Teacher's note: With f1 = 15.2 cm and f2 = 14.9 cm: 14.9 ÷ 15.2 = 0.98, which is above 0.9, so they are equal within the limits. Just writing 'they are close' scores nothing: the calculation is the mark.

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Question 4

28 marks · Thermal properties and temperature

The question

Where students lost marks

Answers were generally strong, especially when they worked through the bullet points in order. Marks went when the extra apparatus (thermometer and stopwatch) wasn't stated, when the five-minute cooling time in the question was replaced by a time of the candidate's own, and when results tables had a rate-of-cooling column but no column for the final temperature that is actually measured. Predictions from theory don't count as conclusions, and 'repeat and average' is too vague unless it is for each starting temperature.

The trap: Your table must hold what you MEASURE: initial and final temperature. Keep the 5 minutes. A prediction is not a conclusion.

Source: Paper 0625/62 (Alternative to Practical), Question 4, June 2025 examiners' report (paraphrased)

Mark scheme, mark by mark

MP1stopwatch and thermometer

MP2heat to a measured temperature, cool for 5 min, measure final temperature

MP3repeat for a new initial temperature

MP4control: volume of water / time / room temperature

MP5table: initial and final temperature with units

MP6conclusion: graph of rate against initial temperature

MP7one more: second control, five sets, repeat each and average, or use the rate formula

Teacher's note: Walk the bullets in order and each one is a mark. Rate of cooling is CALCULATED from the measured temperatures and the 5 minutes, so it can't replace them in the table.

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