Electrical Machines Open circuit in a transformer is prefered with rated transformer voltage rated transformer current high frequency supply direct current rated transformer voltage rated transformer current high frequency supply direct current ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a loaded DC motor, if the brushes are given a shift from the interpolar axis in the direction of rotation, then the commutation will improve and the speed rises. deteriorate and the speed rises. deteriorate and the speed falls. improve and the speed falls. improve and the speed rises. deteriorate and the speed rises. deteriorate and the speed falls. improve and the speed falls. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Saving of copper in auto transformer is increased as compared to two winding transformer, when transformation ratio K approaches to two. unity. zero. infinity. two. unity. zero. infinity. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In DC machine torque depends on which of the following? flux (φ) both A and B armature current (I) speed flux (φ) both A and B armature current (I) speed ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines DC Shunt Motor has disadvantage(s) of constant speed. not suitable for rapidly changing loads. less expensive. none of above. constant speed. not suitable for rapidly changing loads. less expensive. none of above. 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%. 78.5% 72.5% 67.5% 82.5% 78.5% 72.5% 67.5% 82.5% ANSWER DOWNLOAD EXAMIANS APP
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