Electrical Machines Which of the following is/are not a self starting motor? None of these 1-phase induction motor both 1 and 2 3-phase induction motor None of these 1-phase induction motor both 1 and 2 3-phase induction motor ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Due to magnetic saturation, the flux per pole in a DC machine without brush shift increases in both the generators and the motors with load. decreases in both generators and the motors with load. increases in generators but decreases in motor with load. decreases in generators and increases in motor with load. increases in both the generators and the motors with load. decreases in both generators and the motors with load. increases in generators but decreases in motor with load. decreases in generators and increases in motor with 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%. 72.5% 78.5% 82.5% 67.5% 72.5% 78.5% 82.5% 67.5% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is the necessity of copper brushes in a dc motors? To convert alternating supply current to direct current. To increase the flux cutting by the rotor. None of these. To absorb the mechanical shocks produced during running condition. To convert alternating supply current to direct current. To increase the flux cutting by the rotor. None of these. To absorb the mechanical shocks produced during running condition. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In DC generators, the residual magnetism is of the order of 15 %. 2.5 %. 10 %. 20 %. 15 %. 2.5 %. 10 %. 20 %. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A dc shunt motor runs at a no-load speed of 1140 rpm. At full load, armature reaction weakens the main flux by 5% whereas the armature circuit voltage drops by 10%. The motor full-load speed in rpm is 1080 1200 1203 1000 1080 1200 1203 1000 ANSWER DOWNLOAD EXAMIANS APP
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