Electrical Machines High inrush of current during a starting of DC motor can efficiently be restricted to a safer value by increasing the _________________ resistance. both A and B shunt field armature circuit none of above both A and B shunt field armature circuit none of above ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If an AC servomotor has one of its winding excited by AC, then voltage measured at the other winding with rotor running will be zero. constant independent of speed. proportional to square of rotor speed. proportional to rotor speed. zero. constant independent of speed. proportional to square of rotor speed. proportional to rotor speed. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The polarity of a DC generator can be reversed by any of above. reversing the field current. reversing field electric current as well as direction of rotation. increasing field current. any of above. reversing the field current. reversing field electric current as well as direction of rotation. increasing field current. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the load current and flux of a DC motor are held constant and voltage applied across it armature is increased by 5%, the speed of the motor will Depends on other factor. Increase by 5%. Reduce by 5%. Remain unchanged. Depends on other factor. Increase by 5%. Reduce by 5%. Remain unchanged. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When the rotor speed, in a synchronous machine, becomes more than the synchronous speed during hunting, the damper bars develop induction generator torque. synchronous motor torque. induction motor torque. DC motor torque. induction generator torque. synchronous motor torque. induction motor torque. DC motor torque. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature mmf in a dc machine is 1. stationary with respect to field poles 2. stationary with respect to armature 3. rotating with respect to field poles 4. rotating with respect to armature From these, the correct answer is 1, 4 2, 4 2, 3 1, 3 1, 4 2, 4 2, 3 1, 3 ANSWER DOWNLOAD EXAMIANS APP