Electrical Machines For a DC Shunt Motor having armature resistance of 0.5 Ω and 2A armature current at no-load, when the armature current is changed to 20A at loaded condition the speed is 1000 r.p.m. What is the speed at no-load? 4575.4 r.p.m. 1037.5 r.p.m. 963.8 r.p.m. 1130 r.p.m. 4575.4 r.p.m. 1037.5 r.p.m. 963.8 r.p.m. 1130 r.p.m. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Compensating winding are used to rectify the flux density waveform at None of these throughout the air gap. region under main pole. interpole region. None of these throughout the air gap. region under main pole. interpole region. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 5 KVA transformer has a turns ratio of N1/N2 = 10. The impedance of primary winding is 3+j5 ohms while that of secondary winding is 0.5+j0.8 ohms. The impedance of transformer when referred to primary will be 3.05+j5.08 ohms 3.5+j5.8 ohms 8+j13 ohms 53+j85 ohms 3.05+j5.08 ohms 3.5+j5.8 ohms 8+j13 ohms 53+j85 ohms ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Two transformers with identical rating, are designed with flux densities of 1.2 and 1.4 Wb / m2 respectively. The weight of first transformer per kVA is equal to that of second transformer. less than that of second transformer. none of these. more than that of second transformer. equal to that of second transformer. less than that of second transformer. none of these. more than that of second transformer. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following is/are the advantages of carbon brush over the copper brush? All of these They are not hard as copper brush In case of any sparking they will be less damaged than copper brushes They are self lubricating in nature All of these They are not hard as copper brush In case of any sparking they will be less damaged than copper brushes They are self lubricating in nature ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A three phase 400 V, 6 pole, 50 Hz, squirrel cage induction motor is running at a slip of 5%. The speed of stator magnetic field with respect to rotor magnetic field and speed of rotor w.r.t stator magnetic field are zero, 950 rpm. 1000 rpm, - 50 rpm. zero , - 50 rpm. 1000 rpm, 950 rpm. zero, 950 rpm. 1000 rpm, - 50 rpm. zero , - 50 rpm. 1000 rpm, 950 rpm. ANSWER DOWNLOAD EXAMIANS APP
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