单项选择题
A.develop torque
B.generate high voltages
C.produce a magnetic field
D.generate high electrical resistance
单项选择题 The power factor at which a paralleled AC generator operates is usually adjusted by the （）.
单项选择题 If the resistance of a circuit is cut in half and the applied voltage is kept constant, the current flow will be （）.
单项选择题 Equal power factors on paralleled AC generators are maintained by an automatic （）.