Electrical Machines An induction motor has synchronous speed of 1500 rpm. What will be the slip when it is running at a speed of 1450 rpm? +3% +3.33% -3.33% -3% +3% +3.33% -3.33% -3% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 250 volt dc series motor having an armature resistance of 0.2 Ω takes a load current of 60 A. What will be the torque produced at the shaft of the motor? Consider brush drop of 1V. 133.22 N-m can not be determined. 234.76 N-m. 266.20 N-m. 133.22 N-m can not be determined. 234.76 N-m. 266.20 N-m. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements regarding the speed control of dc motors : 1. ward-leonard method is suitable forconstant-torque drives 2. Ward-leonard method is suitable for constant-power drives 3. field-control method facilitates speed control below base speed 4. Armature-resistance control method is more efficient than ward-leanard method 5. Field-control method is suitable for constant-torque drives 6. Armature-resistance control method is suitable for constant-torque drives From these, the correct answer is 1, 2, 6 1, 4, 6 1, 3, 5 1, 2, 5 1, 2, 6 1, 4, 6 1, 3, 5 1, 2, 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines stepped cores are used in transformers in order to reduce volume of iron. reluctance of core. volume of copper. iron loss. volume of iron. reluctance of core. volume of copper. iron loss. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the temperature of armature resistance is increased, the speed of a series motor would decrease. increase. not change. None of above. decrease. increase. not change. None of above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Addition of 0.3 % to 4.5 % silicon to iron increases the electrical resistivity of iron. reduces the saturation magnetization. None of these increases the hysteresis loss. increases the electrical resistivity of iron. reduces the saturation magnetization. None of these increases the hysteresis loss. ANSWER DOWNLOAD EXAMIANS APP
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