Electrical Machines The armature mmf in a dc machine is 1. stationary with respect to field poles 2. stationary with respect to armature 3. rotating with respect to field poles 4. rotating with respect to armature From these, the correct answer is 1, 4 2, 3 1, 3 2, 4 1, 4 2, 3 1, 3 2, 4 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature shaft must be able to with stand All of these Any unbalanced magnetic pull on the armature core. Bending moment due to weight of the armature. Twisting stains due to transmission of torque. All of these Any unbalanced magnetic pull on the armature core. Bending moment due to weight of the armature. Twisting stains due to transmission of torque. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In electric locomotive which of the following motor are used ? DC series motor. Synchronous motor. Separately compound motor. Shunt motor. DC series motor. Synchronous motor. Separately compound motor. Shunt motor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Hunting in a synchronous cannot be due to variable load. variable frequency. variable supply voltage. windage friction. variable load. variable frequency. variable supply voltage. windage friction. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is the full form of MNP? Magnetic neutral plane. Magnetic field neutral plane. Magnetic field neutral pole. Magnetic neutral pole. Magnetic neutral plane. Magnetic field neutral plane. Magnetic field neutral pole. Magnetic neutral pole. 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% 78.5% 72.5% 67.5% 82.5% 78.5% 72.5% 67.5% ANSWER DOWNLOAD EXAMIANS APP
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