Electrical Machines During hunting of a synchronous motor harmonic are developed in the armature circuit. negative phase sequence currents are generated. damper bar develops torque. field excitation increases. harmonic are developed in the armature circuit. negative phase sequence currents are generated. damper bar develops torque. field excitation increases. 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%. 940 RPM 970 RPM 960 RPM 920 RPM 940 RPM 970 RPM 960 RPM 920 RPM ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In case of a DC Shunt motor if the load is decreased to some extent, what will happen to its speed? The speed will increase in proportion to reduction in load. The speed will increase abruptly. The speed will increase gradually. The speed will remains almost constant. The speed will increase in proportion to reduction in load. The speed will increase abruptly. The speed will increase gradually. The speed will remains almost constant. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines To increase starting torque of a 3-phase slip ring induction motor, preferred method is to increase rotor resistance supply frequency supply voltage None of these rotor resistance supply frequency supply voltage None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Mechanical energy is supplied to DC generator at the rate of 4200 J / s. The generator delivers 32.2 Amp at 120 V. What is the percentage efficiency of the generator? 201.02 V. 212 V. 210 V. 205 V. 201.02 V. 212 V. 210 V. 205 V. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines To control the speed of an induction motor, the supply frequency is reduced by 10%. For the same magnetizing current to remain constant, the supply voltage must be increased by 20% reduced by 20% increased by 10% reduced by 10% increased by 20% reduced by 20% increased by 10% reduced by 10% ANSWER DOWNLOAD EXAMIANS APP
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