Is repeating Year 12 with the same A level subjects a bad thing? If so, how does it affect you in terms of UCAS application? Does it mean I am now unlikely to get into G5 universities? By the way, I am planning to do Physics for my undergraduate course.
Would depend on the circumstances i presume. If you were repeating due to ill health or family circumstances i do not see why this would be a negative. Though i expect offers are slightly higher for older candidates. Completely non scientific view but i do not recall anyone really making a massive success of repeating a year (and that includes a few i knew who did a 3rd year 6th (year 14!)). Difficult thing to do psychologically, out of your peer group and feeling a bit of a spare part. Of course everyone is different. Hope it goes well.