Electrical Machines The low voltage winding of a 400/230 V single phase 50 Hz transformer is to be connected to keep the magnetization current at the same level in both the cases the voltage at 25 Hz should be 65 V 460 V 230 V 115 V 65 V 460 V 230 V 115 V ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The field divertor resistance for a DC series motor is of order of 50 Ω 100 Ω 0.1 Ω 10 Ω 50 Ω 100 Ω 0.1 Ω 10 Ω ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a dc machine, 1. physically, the brush axis is along the direct axis 2. physically, the brush axis is along the interpolar axis 3. schematically, the brush axis is along the direct axis 4. schematically, the brush axis is along the quadrature axis 5. armaturemmf is directed along the brush axis From these, the correct statements are 1, 4,5 1 , 3, 5 2, 4, 5 2, 3, 5 1, 4,5 1 , 3, 5 2, 4, 5 2, 3, 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The condition for maximum running torque is zero unity R = S.X 0.5 lagging 0.707 lagging zero unity R = S.X 0.5 lagging 0.707 lagging ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Neglecting all losses, the developed torque (T) of DC separately excited motor, operating under constant terminal voltage is reduced to its output power (P) as T ∝ P. T ∝ √P. T is independent of P. T2 ∝ P3. T ∝ P. T ∝ √P. T is independent of P. T2 ∝ P3. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A dc shunt motor has external resistance Ra and Rf in the armature and field circuits respectively. Armature current at starting can be reduced by keeping Ra maximum and Rf maximum Ra maximum and Rf minimum Rf maximum and Ra minimum Ra minimum and Rf minimum Ra maximum and Rf maximum Ra maximum and Rf minimum Rf maximum and Ra minimum Ra minimum and Rf minimum ANSWER DOWNLOAD EXAMIANS APP
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