Electrical Machines Which of the following is done in speed control of DC motor by field flux control? Inserting an additional resistance in the armature circuit. Inserting an additional resistance in the field circuit. Inserting resistance to armature circuit and field circuit. Any of above. Inserting an additional resistance in the armature circuit. Inserting an additional resistance in the field circuit. Inserting resistance to armature circuit and field circuit. Any of above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Transformer action requires a alternating electric flux. alternating magnetic lux. constant magnetic flux. increasing magnetic flux. alternating electric flux. alternating magnetic lux. constant magnetic flux. increasing magnetic flux. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines An IM cannot run at synchronous speed because none of above. induction motor will become synchronous motor. air friction will prevent it. rotor torque will not be produced. none of above. induction motor will become synchronous motor. air friction will prevent it. rotor torque will not be produced. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Two of supply terminals to a 3 - Φ induction motor get interchanged during re-connection after normal maintenance. When switched on the supply, the motor will rotate in direction opposite to that before maintenance. not start at all. rotate in the same direction as before maintenance. get heated and damaged. rotate in direction opposite to that before maintenance. not start at all. rotate in the same direction as before maintenance. get heated and damaged. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The rotor of a 3 - Φ wound induction motor is provided with heavy short-circuited end rings. single phase winding. heavy copper or aluminium bars placed in rotor slots. three phase winding. heavy short-circuited end rings. single phase winding. heavy copper or aluminium bars placed in rotor slots. three phase winding. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3 - Φ induction motor draws an current of 50 A from mains when starts by direct switching. If an auto transformer with 60 % tapping is used for starting the current drawn from the mains will be 80. 50. 18. 36. 80. 50. 18. 36. ANSWER DOWNLOAD EXAMIANS APP