Electrical Machines In a DC generator, the armature reaction results in magnetization of inter poles. demagnetization of leading & magnetization of trailing pole tip. demagnetization of centers of poles. magnetization of leading and demagnetization of trailing pole tip. magnetization of inter poles. demagnetization of leading & magnetization of trailing pole tip. demagnetization of centers of poles. magnetization of leading and demagnetization of trailing pole tip. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The residual magnetism of a self-excited dc generator is lost. To build up its emf again the field winding must be replaced the field winding connection must be reversed field winding must be excited by low voltage dc supply the armature connection must be reversed the field winding must be replaced the field winding connection must be reversed field winding must be excited by low voltage dc supply the armature connection must be reversed ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines How can the synchronous speed of a 3 - Φ IM be varied? By varying supply voltage. Both (A) and (B). By varying the supply frequency. By varying number of poles. By varying supply voltage. Both (A) and (B). By varying the supply frequency. By varying number of poles. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Armature reaction in DC generators will result in increase in slip. open circuit. short circuit. reduction in generated emf. increase in slip. open circuit. short circuit. reduction in generated emf. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the field of a dc shunt motor gets opened while the motor is running, then the armature current will drop motor will attain dangerously high speed motor will become slow. armature will oscillate about original speed as the mean speed armature current will drop motor will attain dangerously high speed motor will become slow. armature will oscillate about original speed as the mean speed ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Armature reaction in a DC machine is in the same direction as the main poles. makes an angle of 90° with the main pole axis. is in direct opposition to the main poles. makes an angle with the main pole axis which is load dependent. is in the same direction as the main poles. makes an angle of 90° with the main pole axis. is in direct opposition to the main poles. makes an angle with the main pole axis which is load dependent. ANSWER DOWNLOAD EXAMIANS APP
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