Electrical Machines As compared to an induction motor, the air gap in a DC motor is less than 50%. between 50% and 90%. same. more. less than 50%. between 50% and 90%. same. more. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the source voltage of a DC motor is increased, which of the following will decrease? Starting torque. Operating speed. Full load current. Starting torque, operating speed, full load current. Starting torque. Operating speed. Full load current. Starting torque, operating speed, full load current. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The oscillation in a synchronous motor can be damped out by providing damper bars in the rotor pole faces. running the motor on leading power factors. oscillation cannot be damped. maintaining constant excitation. providing damper bars in the rotor pole faces. running the motor on leading power factors. oscillation cannot be damped. maintaining constant excitation. 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%. 82.5% 72.5% 67.5% 78.5% 82.5% 72.5% 67.5% 78.5% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Capacitor in split phase induction motor is used to improve the power factor. reduce the harmonics. start the motor. improve the starting torque. improve the power factor. reduce the harmonics. start the motor. improve the starting torque. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a stepper motor the detente torque means maximum of the static torque with the phase winding excited. maximum of the static torque with the phase winding unexcited. minimum of the static torque with the phase winding excited. minimum of the static torque with the phase winding unexcited. maximum of the static torque with the phase winding excited. maximum of the static torque with the phase winding unexcited. minimum of the static torque with the phase winding excited. minimum of the static torque with the phase winding unexcited. ANSWER DOWNLOAD EXAMIANS APP
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