Electrical Machines Iron losses in a DC machine are independent of variation in speed and voltage. load. voltage. speed. speed and voltage. load. voltage. speed. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Voltage across the open circuited field termninals of a synchorous machine under slip test is AC of supply frequency. DC. A modulated supply frequency AC voltage with slip frequency envelop. DC of slip frequency. AC of supply frequency. DC. A modulated supply frequency AC voltage with slip frequency envelop. DC of slip frequency. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3-phase, 50Hz, 4 pole induction motor is running at 1440 rpm and rotor input power is 2KW. Find the rotor output power? 1450W 1920W 1820W 2000W 1450W 1920W 1820W 2000W ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 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 efficiency when running as a motor taking 40 A at 250 V. Armature reaction weakens the field by 4%. 67.5% 72.5% 78.5% 82.5% 67.5% 72.5% 78.5% 82.5% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If residual magnetism of a shunt generator is destroyed accidentally it may be restored by connecting its shunt field to earth. to a DC source. in reverse. to an AC source. to earth. to a DC source. in reverse. to an AC source. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a synchronous motor when the rotor speed exceeds the synchronous speed during hunting negative sequence currents are generated. the damper bars develop induction generator torque. the damper bars develop synchronous motor torque. the damper bars develop induction motor torque. negative sequence currents are generated. the damper bars develop induction generator torque. the damper bars develop synchronous motor torque. the damper bars develop induction motor torque. ANSWER DOWNLOAD EXAMIANS APP
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