Electrical Machines Motors for fans and pumps are selected in the rpm range 375 to 500. 1440 to 2880. 500 to 720. 720 to 920. 375 to 500. 1440 to 2880. 500 to 720. 720 to 920. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Unbalance 3 - Φ stator currents cause double frequency currents in the rotor. heating of rotor. All of these vibrations. double frequency currents in the rotor. heating of rotor. All of these vibrations. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines φA DC shunt machine generates 250 V on open circuit at 1000 RPM. Armature resistance is 0.5 Ω, field resistance 250 Ω. When running as a motor takes 4 A at 250 V. Calculate the speed when running as a motor taking 40 A at 250 V. Armature reaction weakens the field by 4%. 960 RPM 940 RPM 970 RPM 920 RPM 960 RPM 940 RPM 970 RPM 920 RPM 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 0.5 p.u 0.125 p.u 0.25 p.u 0.75 p.u 0.5 p.u 0.125 p.u 0.25 p.u ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In dc machines, the armature windings are placed on the rotor because of the necessity for generation of voltage development of torque electromechanical energy conversion commutation generation of voltage development of torque electromechanical energy conversion commutation ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Belt conveyors offer _______________ starting torque. medium. zero. high. low. medium. zero. high. low. ANSWER DOWNLOAD EXAMIANS APP