Electrical Machines Maximum power developed by a synchronous motor depends on supply voltage and load angle supply voltage and excitation supply voltage, load angle and excitation excitation and load angle supply voltage and load angle supply voltage and excitation supply voltage, load angle and excitation excitation and load angle ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which slots are used in the rotor of an induction motor? Semi closed slots. Closed slots. Open slots. None of above. Semi closed slots. Closed slots. Open slots. 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%. 82.5% 78.5% 72.5% 67.5% 82.5% 78.5% 72.5% 67.5% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3-φ alternator has negligible stator resistance. A short circuit test is conducted on this alternator. At a particular speed, a field current of If1 is required to drive the rated armature current. If the speed of the alternator is reduced to half, the field current required to maintain rated armature current Would be equal to If1. Would be equal to If1/2. Woud be equal to 2If1. Cannot be predicted due to insufficient data. Would be equal to If1. Would be equal to If1/2. Woud be equal to 2If1. Cannot be predicted due to insufficient data. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines It is an advisable to use auto transformer if the transformation ratio is 0.5. Greater than 1. 0.25. near to 1. 0.5. Greater than 1. 0.25. near to 1. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a 3 - Φ IM with line frequency f1 and winding factor kw1 and kw2 for stator and rotor respectively the ratio of per phase stator winding emf E1 to per phase rotor winding emf E2 at standstill is given by E1 / E2 = N1 / N2. E1 / E2 = 1. E1 / E2 = N1kw1 / N2kw2. E1 / E2 = f1kw1 / f2kw2. E1 / E2 = N1 / N2. E1 / E2 = 1. E1 / E2 = N1kw1 / N2kw2. E1 / E2 = f1kw1 / f2kw2. ANSWER DOWNLOAD EXAMIANS APP
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