Electrical Machines Motors for fans and pumps are selected in the rpm range 500 to 720. 1440 to 2880. 720 to 920. 375 to 500. 500 to 720. 1440 to 2880. 720 to 920. 375 to 500. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines During hunting of a synchronous motor damper bar develops torque. field excitation increases. harmonic are developed in the armature circuit. negative phase sequence currents are generated. damper bar develops torque. field excitation increases. harmonic are developed in the armature circuit. negative phase sequence currents are generated. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Open circuit in a transformer is prefered with rated transformer voltage direct current rated transformer current high frequency supply rated transformer voltage direct current rated transformer current high frequency supply ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Crawling in an induction motor is due to insufficient starting torque. time harmonics in supply. space harmonics produced by winding currents. slip ring rotor. insufficient starting torque. time harmonics in supply. space harmonics produced by winding currents. slip ring rotor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A dc series motor driving and electric train faces a constant power load. It is running at rated speed and rated voltage. If the speed has to be brought down to 0.25 p.u. the supply voltage has to be approximately brought down to 0.75 p.u 0.125 p.u 0.5 p.u 0.25 p.u 0.75 p.u 0.125 p.u 0.5 p.u 0.25 p.u ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The speed of a DC series motor is Inversely proportional to the armature current. Proportional to field current. Proportional to the armature current. Proportional to the square of the armature current. Inversely proportional to the armature current. Proportional to field current. Proportional to the armature current. Proportional to the square of the armature current. ANSWER DOWNLOAD EXAMIANS APP