Electrical Machines In a synchronous motor when the rotor speed exceeds the synchronous speed during hunting the damper bars develop induction generator torque. the damper bars develop induction motor torque. the damper bars develop synchronous motor torque. negative sequence currents are generated. the damper bars develop induction generator torque. the damper bars develop induction motor torque. the damper bars develop synchronous motor torque. negative sequence currents are generated. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 500 V, 120 KW, 50 Hz, star connected synchronous motor operating at 0.8 power factor leading has full load efficiency of 91%. The armature resistance is equal to 0.08Ω. The magnitude of armature current is nearly equal to 240 A. 190 A. 173 A. 127 A. 240 A. 190 A. 173 A. 127 A. 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, 5 1, 4, 6 1, 2, 6 1, 3, 5 1, 2, 5 1, 4, 6 1, 2, 6 1, 3, 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The rotor speed of an induction motor is given by Ns = 120f / p × ( 1 - s ). None of these Ns = 120f /p × ( 1 - r). Nr = 120f / p × (1-s). Ns = 120f / p × ( 1 - s ). None of these Ns = 120f /p × ( 1 - r). Nr = 120f / p × (1-s). ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The slip of an induction motor normally does not depend on which of the following? Core loss component. Rotor speed. Shaft torque. Synchronous speed. Core loss component. Rotor speed. Shaft torque. Synchronous speed. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 4 pole DC shunt generator having a wave winding supplies 50 lamps, each of 60 W at 120 V. The armature and field resistance are 0.2 Ω and 60 Ω respectively. The current in each armature conductor is 13.5 A. 23 A. 11.5 A. 27 A. 13.5 A. 23 A. 11.5 A. 27 A. ANSWER DOWNLOAD EXAMIANS APP
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