Electrical Machines In dc machines, the field-flux axis and armature-mmf axis are respectively along direct axis and indirect axis direct axis and interpolar axis quadrature axis and direct axis quadrature axis and interpolar axis direct axis and indirect axis direct axis and interpolar axis quadrature axis and direct axis quadrature axis and interpolar axis ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The sparking at the the brushes, in a DC machines is due to high resistance of carbon brushes. presence of commutator. armature reaction. reactance voltage. high resistance of carbon brushes. presence of commutator. armature reaction. reactance voltage. 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 1000 rpm, - 50 rpm. zero, 950 rpm. 1000 rpm, 950 rpm. zero , - 50 rpm. 1000 rpm, - 50 rpm. zero, 950 rpm. 1000 rpm, 950 rpm. zero , - 50 rpm. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is the frequency of a alternator, if P = number of poles and N = revolution made per second? 120N / P Hz. PN / 2 Hz. 120 / PN Hz. 120P / N Hz. 120N / P Hz. PN / 2 Hz. 120 / PN Hz. 120P / N Hz. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Maximum allowable tan - delta (tanδ) of dielectric dispassion factor of power transformer insulating oil is generally taken as 0.5 at 90°C. 2 at 90°C. 1 at 90°C. 3 at 90°C. 0.5 at 90°C. 2 at 90°C. 1 at 90°C. 3 at 90°C. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is the increase in the torque expressed as percentage of initial torque, if current drawn by the dc series motor is increased from 10A to 11A? 11% 41% 21% 10% 11% 41% 21% 10% ANSWER DOWNLOAD EXAMIANS APP
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