Media, film and TV studies has overtaken physics in popularity as an A-level subject this summer.
The exam boards say changes simply reflect student choices
Those sitting physics exams dropped 2% to 28,119, while those choosing media subjects increased by 5.1% to 28,261.
The Institute of Physics said it was "crazy" that students were opting for subjects with "poor career prospects".
But Ellie Johnson Searle, director of the Joint Council for Qualifications, said they were making choices which suited their talents and future plans.
French in decline
The number of entries in subjects defined by the JCQ as "traditional" - English, art, classical studies, economics, geography, history, maths and RE - was 244,707.
The number in "newer" subjects - politics, psychology, law, media and sociology - was 122,461.
These equate to 31.2% and 15.6% of entries respectively.
Foreign languages entries rose overall, with Russian, Italian and Chinese accounting for much of the change.
But French entries fell by 4.4% to 14,484 and German by 7.7% to 5,901.
Dr Johnson Searle described the situation in French as "stark", adding that it had halved in popularity at A-level over the last 11 years.
Spanish entries, however, increased by 4.4% to 6,230 this year, overtaking German.
Dr Johnson Searle said the figure for physics was an "anomaly" among the general rise in science subjects, but students were basing their choices on their needs for work and gaining a place on a degree course.
Physics was less likely to be taken as a "third A-level" by non-science specialists than biology, for instance.
She added that universities were also less likely to ask for an A-level in physics than in chemistry, which increased 4.3% in popularity to 38,851 entries.
Robert Kirby-Harris, chief executive of the Institute of Physics, said the crucial issue was not whether A-levels were getting easier.
"It's about whether students are making the right choices of subject - choices which will give them the range of career opportunities they want and which will give the UK the supply of well qualified school-leavers that it needs.
"Students who take physics at A-level enjoy higher salaries in later life and have a much wider variety of career options open to them," he said.
"It's a crazy situation and we need to put more resources into good quality careers advice in schools."
Education minister Lord Adonis said: "I welcome the overall improvement in science entries, but the fall in numbers taking physics is a concern and we will continue to work closely with employers, schools and experts in the field to improve uptake, not least by girls."
Lord May, president of the Royal Society, said: "We are still facing a crisis in physics, maths and chemistry at A-level."
Entries in physics had decreased by 35.2% since 1991, while those in maths and chemistry had fallen by 21.5% and 12.6%, he added.
More than three quarters of this year's A-level physics candidates were male.
Added to this, the pass rate among boys rose by 0.5 of a percentage point but dropped by 0.6 of a point among girls.
Dr Johnson Searle said A-levels were still the "gold standard" and the public could be "very confident" about quality being maintained.
This summer, biology entries increased by 3.3% to 53,968.
This means it has overtaken maths, which itself gained 0.2% more entries than in 2004, with 52,897.
This was the only shift in the "top 10" A-level table, which English still heads with 85,858 entries - 11% of those for all subjects.
Numbers of students taking business studies, computing and information technology all fell.
Dr Johnson Searle said the focus in these areas was becoming more vocational, with industry-based courses gaining in popularity at the expense of A-levels.
Students typically already known their results in those courses, which are not released in the same way as A-levels.