go to
first year course information & click on "course availability" & read this entry and the one below it on choosing your 1st year physics course.
my son studies pv eng, did both mx1 & mx2 in 2008 hsc but not physics. He chose to do phys1111 fundamentals of physics in session 1 (scored a 97 hd), then higher physics 1a in session 2 (got a 77 dn). He studied equally hard for both so it gives you some idea of the difficulty difference between fundamentals (which is harder than hsc physics) & higher physics 1a. He's currently finishing higher physics 1b in summer session.
Get some serious advice from the ee school office - they will be able to best guide you.
Best of luck.
Edit: In case you're confused, this is unsw specific info - didn't realise i was in a general engineering thread when i posted this reply.