The performance of Higher physics candidates rose for the third year running, with well over three quarters of pupils achieving an A, B or C grade; 13 per cent walked away with no award.
Markers, however, lamented the fact that while questions requiring candidates to perform calculations were generally answered very well, most candidates performed poorly in those requiring written descriptions and explanations.
Question 21b, for instance, where candidates were asked to describe the vertical motion of a helicopter immediately after a crate had been dropped, was poorly answered, they said.
The ability to write descriptive answers and explanations was likely to receive "at least as much, or even more, emphasis in future assessment", they warned.
The examiners also commented that the correct use and spelling of technical words or expressions was important.
"Candidates at Higher should not be writing expressions such as `deconstructive interference' (it should be destructive interference) or `lazer'," they said.
At Intermediate 2, similar problems were identified, with candidates "still underperforming in questions requiring definitions, explanations and descriptions".
Candidates struggled with multiple-choice questions 5, 6, 10, 13 and 16, which covered latent heat, work done, mains supply, waves, and the power of a lens.
Markers also recommended that teachers remind Intermediate 2 pupils to include units in their final answers, to use the correct units, to round numerical answers appropriately and to avoid the use of too many significant numbers. These were also highlighted as problem areas by Higher physics markers, and incorrect or missing units lost Intermediate 1 candidates marks.
At Standard grade the picture regarding pupils' use of English was more positive. Most candidates were able to express themselves "clearly and precisely" when answering questions requiring explanations or descriptions, said examiners.