Electrical Machines If Kh is hysteresis constant, f is supply frequency, Bm maximum flux density in core of transformer, the expression of hysteresis loss in transformer, is given by KhfBm3. KhfBm. Khf2Bm1.6. KhfBm1.6. KhfBm3. KhfBm. Khf2Bm1.6. KhfBm1.6. 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 Would be equal to If1. Cannot be predicted due to insufficient data. Would be equal to If1/2. Woud be equal to 2If1. Would be equal to If1. Cannot be predicted due to insufficient data. Would be equal to If1/2. Woud be equal to 2If1. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Transformer cooling and insulating oil must be of low BDV. low resistivity. high viscosity. low viscosity. low BDV. low resistivity. high viscosity. low viscosity. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In case of DC Shunt Motor, the speed will____ if the voltage increases, neglecting armature saturation. be unpredictable. decrease. remain the same. increase be unpredictable. decrease. remain the same. increase ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3 - Φ induction motor draws an current of 50 A from mains when starts by direct switching. If an auto transformer with 60 % tapping is used for starting the current drawn from the mains will be 80. 50. 18. 36. 80. 50. 18. 36. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The DC generator runs at a speed of 1000 rpm and flux per pole is 0.2 Wb, number of poles are 2 the winding is wave wound and having 480 conductors. The critical speed is 1200 rpm. Then the generated emf ( Eg ) 2000 Volt. 1600 Volt. 0 Volt. 1500 Volt. 2000 Volt. 1600 Volt. 0 Volt. 1500 Volt. ANSWER DOWNLOAD EXAMIANS APP
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