Electrical Machines Reactive power generated or delivered significantly depends on excitation. both 1 and 2. frequency. load angle. excitation. both 1 and 2. frequency. load angle. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following factors improve commutation in a dc machine ? 1. High contact resistance of brushes 2. High inductance of the coils undergoing commutation 3. Shifting of brushes in the direction of rotation for a generator and in the opposite direction For a motor 4. Narrow width for the commutation bars Select the correct answer using the codes given below : Codes : 1, 2 and 4 2, 3 and 4 1, 2, and 3 1 and 3 1, 2 and 4 2, 3 and 4 1, 2, and 3 1 and 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature of DC machine is made of silicon steel lamination to increase the permeability. reduce hysteresis loss only. reduce both eddy current and hysteresis loss. reduce eddy current loss only. increase the permeability. reduce hysteresis loss only. reduce both eddy current and hysteresis loss. reduce eddy current loss only. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is the frequency of a alternator, if P = number of poles and N = revolution made per second? PN / 2 Hz. 120N / P Hz. 120P / N Hz. 120 / PN Hz. PN / 2 Hz. 120N / P Hz. 120P / N Hz. 120 / PN Hz. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Series booster is a shunt wound DC generator. permanent magnet DC generator. separately excited DC generator. series wound DC generator. shunt wound DC generator. permanent magnet DC generator. separately excited DC generator. series wound DC generator. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines To have sparkless commutation, the armature reaction effect in a DC machine is neutralized by compensating winding and commutating poles. fixing the brush axis inline with the pole axis. increasing field excitation. shifting the brush axis from GNA to MNA. compensating winding and commutating poles. fixing the brush axis inline with the pole axis. increasing field excitation. shifting the brush axis from GNA to MNA. ANSWER DOWNLOAD EXAMIANS APP
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