Electrical Machines The current drawn by a 220 V DC series motor of armature resistance 0.5 Ω and back emf of 200 V is 400 A. 40 A. 440 A. 44 A. 400 A. 40 A. 440 A. 44 A. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For pure resistive load what is the armature reaction? cross magnetization magnetization All of these demagnetization cross magnetization magnetization All of these demagnetization ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Compensating windings are used in DC generators to neutralize the cross magnetizing effect of the armature reaction. mainly to reduce the eddy currents by providing local short circuit. None of these to provide path for the circulation of cooling air. to neutralize the cross magnetizing effect of the armature reaction. mainly to reduce the eddy currents by providing local short circuit. None of these to provide path for the circulation of cooling air. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC series motor has which of the following characteristics? Has its field winding consinting of thick wire and less no of turns. Has a almost constant speed. Can be started easily without load. Has a poor torque. Has its field winding consinting of thick wire and less no of turns. Has a almost constant speed. Can be started easily without load. Has a poor torque. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is power factor of a 3 - φ induction motor at no load? Equal to 1. High. Low. Same as full load. Equal to 1. High. Low. Same as full load. 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% 82.5% 78.5% 67.5% 72.5% 82.5% 78.5% ANSWER DOWNLOAD EXAMIANS APP
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