New A-levels designed to give bright pupils more "stretch and challenge" contained questions that were too easy, the exams watchdog reported today.
Ofqual looked at six of the qualifications, first taken by pupils last year, and found that half had sections that were not demanding enough.
"In several instances, the written papers did not provide appropriate opportunities for the full range of candidates to demonstrate what they knew, understood and could do," the watchdog said.
Two written papers for Edexcel's physics A-level did not have enough "stretch and challenge", Ofqual found. They also provided only "limited opportunities" for pupils to earn credit for extended responses.
Coursework for the same qualification had marking criteria that was not tough enough to allow sufficient discrimination between different candidates' performance.
AQA's English literature B contained some optional questions that were "not appropriately demanding", the watchdog reports.
It said the same board's geography A2 exam also contained questions that were too easy, with one not representing enough progression from AS level. But another question in the same paper was too hard, partly because of complicated wording. However, the watchdog concluded that "in general" the papers it looked at "contained an appropriate degree of stretch and challenge".
"A-levels overall are continuing to meet the standards set for such important qualifications," an Ofqual spokesperson said.
Andrew Hall, AQA chief executive, said: "This type of work is a key part of Ofqual's role and we support it."
An Edexcel spokesperson said: "We have already agreed next steps with Ofqual regarding their concerns around some physics papers and will ensure that any future specifications address them fully."