Electrical Machines A large series motor is never started without some mechanical on it because otherwise it will Open fuse or circuit breaker. Draw too much current. Develop excessive speed and damage itself. Produce sparking at brushes. Open fuse or circuit breaker. Draw too much current. Develop excessive speed and damage itself. Produce sparking at brushes. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For a DC Shunt Motor having armature resistance of 0.5 Ω and 2A armature current at no-load, when the armature current is changed to 20A at loaded condition the speed is 1000 r.p.m. What is the speed at no-load? 1037.5 r.p.m. 1130 r.p.m. 4575.4 r.p.m. 963.8 r.p.m. 1037.5 r.p.m. 1130 r.p.m. 4575.4 r.p.m. 963.8 r.p.m. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The short circuit test on a transformer is conducted to obtain core loses only. hysteresis loss. copper losses. eddy current loss. core loses only. hysteresis loss. copper losses. eddy current loss. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Series generators are used in which of the following applications? Arc welding. Used as boosters in dc distribution or transmission. Air crafts. All of these Arc welding. Used as boosters in dc distribution or transmission. Air crafts. All of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines As compared to an induction motor, the air gap in a DC motor is between 50% and 90%. more. same. less than 50%. between 50% and 90%. more. same. less than 50%. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3-φ alternator has negligible stator resistance. A short circuit test is conducted on this alternator. At a particular speed, a field current of If1 is required to drive the rated armature current. If the speed of the alternator is reduced to half, the field current required to maintain rated armature current Woud be equal to 2If1. Would be equal to If1/2. Cannot be predicted due to insufficient data. Would be equal to If1. Woud be equal to 2If1. Would be equal to If1/2. Cannot be predicted due to insufficient data. Would be equal to If1. ANSWER DOWNLOAD EXAMIANS APP
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