The exams CAN be the same, since if you've done the 'ppl' ones, they'll serve for both.
Most Microlighters take a simplified set of tests, which one text will get you through. (Cosgrove)
If you move on to the PPL/NPPL, you'll have another 6 tests to do, with a lot more content. You'll need a set of books(Pratt or Thom), one for each exam.
CG