9) A 10 pole AC generator rotates at 1200 rpm. The frequency of AC voltage in cycles per second will be: a) 120 b) 60 c) 100 d) 160 10) The synchronous machine will not operate if: a) It is not loaded. b) It has no residual flux. c) The filed resistance is greater than the critical value. d) The power angle is more than 90 degrees. 11) To connect several synchronous generators together in parallel: a) They must all rotate at the same speed b) They must all have the same frequency c) They must all have the same power rating d) They must all have the same number of poles 12) Synchronous generators are attractive because: a) They can operate at any speed so they fit with any application b) They are only built with big rated capacity to cope with bulk generation c) They produce output power at constant frequency d) They can produce ac or dc outputs