Electrical Machines which of the following losses are negligible in blocked rotor test? mechanical loss iron loss copper loss both A and B mechanical loss iron loss copper loss both A and B ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When the mechanical power is developed by a DC motor maximum Back emf is equal. None of above. back emf is equal to applied voltage. Back emf is equal to half of applied voltage. Back emf is equal. None of above. back emf is equal to applied voltage. Back emf is equal to half of applied voltage. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The counter (or back) emf in a dc machine is 1. the same as generated emf in a dc motor 2. proportional to field flux and armature speed 3. not the same as generated emf in a dc motor 4.inversely proportional to field flux 5. proportional to number of armature conductors 6. constant from no load to full load From these, the correct answer is 1, 2, 5 3, 4, 5 2, 4, 5, 6 2, 3, 6 1, 2, 5 3, 4, 5 2, 4, 5, 6 2, 3, 6 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC Motor is driving a constant load torque having armature resistance of 0.25 Ω and armature current of 60 A having connected to a voltage of 230 V. Now a resistance of 1 ohm is added into the armature circuit. The ratio of their speed will be 1.24. 0.62. 0.25. 0.72. 1.24. 0.62. 0.25. 0.72. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A synchorous generator connected to an infinite bus is over excited. Considering only the reactive power from the point view of the system the machine acts as an inductor. A capacitor. A resistor. None of these. an inductor. A capacitor. A resistor. None of these. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The main purpose of providing tertiary winding in a three phase transformer is to suppress harmonic and unbalance in voltage. to interconnect three voltage systems. to carry extra load. None of these to suppress harmonic and unbalance in voltage. to interconnect three voltage systems. to carry extra load. None of these ANSWER DOWNLOAD EXAMIANS APP
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