Electrical Machines The armature reaction mmf in a DC machines has a form of sinusoidal. rectangular. triangular. trapezoidal. sinusoidal. rectangular. triangular. trapezoidal. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Maximum allowable tan - delta (tanδ) of dielectric dispassion factor of power transformer insulating oil is generally taken as 1 at 90°C. 2 at 90°C. 0.5 at 90°C. 3 at 90°C. 1 at 90°C. 2 at 90°C. 0.5 at 90°C. 3 at 90°C. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In dc machines, the field system has to be provided on stator unlike synchronous machines Where in it could be on any member, because it gives more uniform air-gap flux distribution it reduces field structure iron losses commutator action is not possible otherwise dc machines are comparatively low rating machines. it gives more uniform air-gap flux distribution it reduces field structure iron losses commutator action is not possible otherwise dc machines are comparatively low rating machines. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is/are the necessary conditions for parallel operation of alternators? Both 1and 2 Speed of alternators should be same Frequency should be same Terminal voltage is same Both 1and 2 Speed of alternators should be same Frequency should be same Terminal voltage is same ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a transformer operating at constant voltage if the input frequency increases, the core loss decrease. None of these remains constant. increase. decrease. None of these remains constant. increase. 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? 21% 41% 11% 10% 21% 41% 11% 10% ANSWER DOWNLOAD EXAMIANS APP