Unless things have changed dramatically, the theory test is worryingly easy. The only real bit which I found a challenge was the hazard perception test.
For those of us who have been driving for years, if we are competent drivers, it
should be easy for us to get at least a pass mark.
It is still a hell of a lot more rigorous than the "theory" test when I took it (1978), which consisted of eth examiner at the end of the test asking a couple of questions, then showing you a few images of road signs and asking what they meant. Mine even gave me a big hint, when one of the signs was red bars on a white background, the usual 3,2,1. I said it was three hundred, two hundred and one hundred yards to something, but I couldn't recall what, and he said "think about trains"!