Electrical Machines Oil is provided in an oil filled transformer for insulating. lubrication. cooling. both cooling and insulation. insulating. lubrication. cooling. both cooling and insulation. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following machine is invariably provided with forced ventilation? 50 MW generator in a power plant. Hermetically sealed motor of refrigerator. Fractional horse power high speed motor. Fractional horse power slow speed motor. 50 MW generator in a power plant. Hermetically sealed motor of refrigerator. Fractional horse power high speed motor. Fractional horse power slow speed motor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 400 V, 50 Hz, 30 Hp, three phase IM is drawing 50 A current at 0.8 p.f lagging. The stator and rotor copper losses are 1.5 KW and 900 W respectively. The friction and windage losses are 1050 W and core losses are 1200 W. The air gap power of the motor will be 25 kW. 26.21 kW. 23.06 kW. 24.11 kW. 25 kW. 26.21 kW. 23.06 kW. 24.11 kW. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The direction of generated emf in the armature coil of a DC machine is 1. the same as that of the current in a generator 2. the same as that of the current in a motor 3. opposite to that of the current in a generator 4. opposite to that of the current in a motor From these, the correct answer is 1, 3 2, 4 2, 3 1, 4 1, 3 2, 4 2, 3 1, 4 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A compound dc generator is delivering full load current at a terminal voltage of 230 V. Its series-field winding gets short circuited. If its terminal voltage 1. becomes more than 230 V, it is overcompounded generator 2. becomes more than 230 V, it is differentially compounded generator 3. becomes less than 230 V, it is overcompounded generator 4. becomes less than 230 V, it is differentially compounded generator 5. becomes less than 230 V, it is level compounded generator From these, the correct answer is 1, 4, 5 2,3 1, 4 2, 3, 5 1, 4, 5 2,3 1, 4 2, 3, 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The starting resistance of DC motor is generally Infinitely large. around 500 ohms. Low. 1000 ohms. Infinitely large. around 500 ohms. Low. 1000 ohms. ANSWER DOWNLOAD EXAMIANS APP
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