Electrical Machines In DC motors, under trailing pole tips, flux density will_______ ? None of these decrease increase either increase or decrease None of these decrease increase either increase or decrease ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature of DC machine is made of silicon steel lamination to reduce hysteresis loss only. reduce eddy current loss only. reduce both eddy current and hysteresis loss. increase the permeability. reduce hysteresis loss only. reduce eddy current loss only. reduce both eddy current and hysteresis loss. increase the permeability. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Type of single phase motor having highest power factor at full load is shaded pole type. capacitor start. split phase. capacitor run. shaded pole type. capacitor start. split phase. capacitor run. 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. 120P / N Hz. 120 / PN Hz. 120N / P Hz. PN / 2 Hz. 120P / N Hz. 120 / PN Hz. 120N / P Hz. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines An auto transformer having a transformation ratio of 0.8 supplies a load pf 10 KW. The power transfered inductively from the primary to secondary is 10 KW. 2 KW. 0. 8 KW. 10 KW. 2 KW. 0. 8 KW. 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 and 3 1, 2, and 3 1, 2 and 4 2, 3 and 4 1 and 3 1, 2, and 3 ANSWER DOWNLOAD EXAMIANS APP