Electrical Machines A 230 volt dc motor has an armature winding resistance of 0.5 ohm. Calculate the emf induced by the motor if the full load armature current is 23 ampere. 220.4 volt. 218.5 volt. 120 volt. None of these. 220.4 volt. 218.5 volt. 120 volt. None of these. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Under which of the following conditions hunting of synchronous motor is likely to occur ? Periodic variation of load. Over-loading for long period. Small and constant load. Over-excitation. Periodic variation of load. Over-loading for long period. Small and constant load. Over-excitation. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements regarding the magnetization characteristics of a dc generator : 1. It represents the variation of field flux with field current. 2. Variation of open-circuit terminal voltage with field current is independent of speed 3. It is non-linear from zero to rated field current 4. It helps to determine the critical field resistance at a given speed 5. It always starts from the origin Which of these statements are correct ? 3 and 5 2, 3 and 4 1 and 4 1, 2 and 5 3 and 5 2, 3 and 4 1 and 4 1, 2 and 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For same HP rating and full load speed which of following motor has poor starting torque? Shunt. Cummulative compound. Differently compounded. Series. Shunt. Cummulative compound. Differently compounded. Series. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Neglecting all losses, the developed torque (T) of DC separately excited motor, operating under constant terminal voltage is reduced to its output power (P) as T ∝ √P. T is independent of P. T2 ∝ P3. T ∝ P. T ∝ √P. T is independent of P. T2 ∝ P3. T ∝ P. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature of DC machine is made of silicon steel lamination to increase the permeability. reduce hysteresis loss only. reduce eddy current loss only. reduce both eddy current and hysteresis loss. increase the permeability. reduce hysteresis loss only. reduce eddy current loss only. reduce both eddy current and hysteresis loss. ANSWER DOWNLOAD EXAMIANS APP
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