THE STUDENT PILOT WAS ON A PRIVATE PILOT CHECK FLIGHT WITH A DESIGNATED FLIGHT EXAMINER. WHILE DEMONSTRATING BALKED LANDINGS, THE GO-AROUND PROCEDURE WAS IMPROPER. THEREFORE, THE EXAMINER ASKED THE STUDENT TO REPEAT THE PROCEDURE ON THE NEXT APPROACH (A SHORT FIELD LANDING APPROACH). DURING THE APPROACH, THE AIRCRAFT HAD DRIFTED TO THE RIGHT WHEN THE GO-AROUND WAS INITIATED. REPORTEDLY, THE NOSE GEAR CONTACTED A 2 FT BURR ALONG THE EDGE OF THE RUNWAY. THE FLIGHT EXAMINER STATED THAT APPARENTLY THE STUDENT HAD RAISED THE FLAPS FULL UP WHEN HE INITIATED THE GO-AROUND. AT THAT POINT, THE EXAMINER TOOK THE CONTROLS AND ATTEMPTED TO GET THE AIRCRAFT BACK ON THE RUNWAY AND STOPPED, SINCE IT HAD SLOWED DOWN TOO MUCH TO CLEAR A 30 FT POWER LINE AT THE END OF THE RUNWAY. HOWEVER, DURING TOUCHDOWN, THE PLANE NOSED OVER. DURING THE ACCIDENT SEQUENCE, THE NOSE WHEEL WAS DRIVEN COMPLETELY AFT.