Electrical Machines Which of the following pairs is/are correct? semi closed slot-----leakage flux is moderate open slot----- leakage flux is less closed slot----- leakage flux is high All of these semi closed slot-----leakage flux is moderate open slot----- leakage flux is less closed slot----- leakage flux is high All of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The mechanical power is developed by a DC motor is maximum when back emf is equal to twice of applied voltage. back emf is equal to applied voltage. none of above. back emf is equal to half of applied voltage. back emf is equal to twice of applied voltage. back emf is equal to applied voltage. none of above. back emf is equal to half of applied voltage. 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%. 970 RPM 940 RPM 960 RPM 920 RPM 970 RPM 940 RPM 960 RPM 920 RPM ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In 3 - Φ induction motor some times copper bars are placed deep in the rotor to improve starting torque. reduce copper loss. improve efficiency. improve power factor. improve starting torque. reduce copper loss. improve efficiency. improve power factor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines To achieve spark less commutation brushes of DC generator are rocked ahead so as to bring them in magnetic neutral axis. just ahead of magnetic neutral axis. just behind the magnetic neutral axis. None of these in magnetic neutral axis. just ahead of magnetic neutral axis. just behind the magnetic neutral axis. None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following motor has negative speed regulation? Differential compound motor Shunt motor Cumulative compound motors Series motor Differential compound motor Shunt motor Cumulative compound motors Series motor ANSWER DOWNLOAD EXAMIANS APP
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