FRQs for circuits:
http://apcentral.collegeboard.com/apc/public/repository/ap10_frq_physics_b_formb.pdf
2010, Form B, question 4, parts a and b only
http://apcentral.collegeboard.com/apc/public/repository/ap07_physb_frq_053107.pdf
2007, question 3
http://apcentral.collegeboard.com/apc/public/repository/ap07_physb_formb_frq.pdf
2007, Form B, question 3 (VERY HARD)
http://apcentral.collegeboard.com/apc/public/repository/ap03_frq_physics_b__23086.pdf
2003, Form B, question 2
