Electrical Machines Semi closed slots or totally closed slots are used in induction motors, essentially to reduce magnetising current and improve power factor improve starting torque increase pull out torque decrease starting torque reduce magnetising current and improve power factor improve starting torque increase pull out torque decrease starting torque 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. 3 at 90°C. 0.5 at 90°C. 1 at 90°C. 2 at 90°C. 3 at 90°C. 0.5 at 90°C. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The wound rotor type IM is used for____________ speed operation. variable. maximum. constant. minimum. variable. maximum. constant. minimum. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 220 ,V 15 , kW 100 rpm shunt motor with armature resistance of 0.25 , W has a rated line current of 68 A and a rated field current of 2.2 A. The change in field flux required to obtain a speed of 1600 rpm while drawing a line current of 52.8 A and a field current of 1.8 A is 36.36% decrease 36.36% increase 36.36% increase 18.18% increase 36.36% decrease 36.36% increase 36.36% increase 18.18% increase ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following windings are necessary in case of all dc machines? wave winding closed winding open type winding lap winding wave winding closed winding open type winding lap winding ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Addition of 0.3 % to 4.5 % silicon to iron None of these reduces the saturation magnetization. increases the hysteresis loss. increases the electrical resistivity of iron. None of these reduces the saturation magnetization. increases the hysteresis loss. increases the electrical resistivity of iron. ANSWER DOWNLOAD EXAMIANS APP