Electrical Machines Transformer cooling and insulating oil must be of high viscosity. low viscosity. low resistivity. low BDV. high viscosity. low viscosity. low resistivity. low BDV. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The result of slip test on a 3-phase, 20 KVA, 400 V, 50 Hz connected salient pole alternator is given below- Phase value: Vmax = 100 V, Vmin = 96 V, Imax = 10 A and I min = 7 A. The direct and quadranature axis reactances are respectively 14.28 and 9.60 Ω. 14.28 and 5.54 Ω. 8.248 and 5.54 Ω. 8.248 and 9.60 Ω. 14.28 and 9.60 Ω. 14.28 and 5.54 Ω. 8.248 and 5.54 Ω. 8.248 and 9.60 Ω. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the applied voltage of a DC motor is 230 V, then back emf, for maximum power developed is 115 V. 460 V. 230 V. 200 V. 115 V. 460 V. 230 V. 200 V. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the excitation is increased, the power factor is unity power factor None of these leading power factor lagging power factor unity power factor None of these leading power factor lagging power factor ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider a separately excited DC motor. If the field current is increased while the armature terminal voltage is held constant, then speed of the motor will remains same. none of these. increase. Decrease.d remains same. none of these. increase. Decrease.d ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a dc machine, the demagnetizing effect of armature reaction is due to component of armature mmf along field axis magnetic saturation in half of the field pole non-sinusoidal nature of armature mmf uneven air-gap length component of armature mmf along field axis magnetic saturation in half of the field pole non-sinusoidal nature of armature mmf uneven air-gap length ANSWER DOWNLOAD EXAMIANS APP