Electrical Machines The field divertor resistance for a DC series motor is of order of 0.1 Ω 50 Ω 10 Ω 100 Ω 0.1 Ω 50 Ω 10 Ω 100 Ω ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 220 ,V 15 , kW 100 rpm shunt motor with armature resistance of 0.25 , W has a rated line current of 68 A and a rated field current of 2.2 A. The change in field flux required to obtain a speed of 1600 rpm while drawing a line current of 52.8 A and a field current of 1.8 A is 36.36% increase 36.36% decrease 36.36% increase 18.18% increase 36.36% increase 36.36% decrease 36.36% increase 18.18% increase ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Ward-Leonard system for controlling the speed of a DC motor is used where All of above. The speed in both the direction is required. The accuracy in speed control is required. Very fine speed control over the whole range from zero to normal speed is required. All of above. The speed in both the direction is required. The accuracy in speed control is required. Very fine speed control over the whole range from zero to normal speed is required. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The full load copper loss and iron loss of transformer are 6400W and 5000W respectively. The copper loss and iron loss at half load will be respectively? 1600 W and 1250 W 3200 W and 2500 W 1600 W and 5000 W 3200 W and 5200 W 1600 W and 1250 W 3200 W and 2500 W 1600 W and 5000 W 3200 W and 5200 W 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 and 3 1, 2 and 4 1, 2, and 3 2, 3 and 4 1 and 3 1, 2 and 4 1, 2, and 3 2, 3 and 4 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 4 pole DC generator runs at 750 rpm and generate an emf of 240 V. The armature is wave wound and has 792 conductors. If the total flux from each pole is 0.0145 Wb. What is the leakage co-efficient? 1.2. 1.5. 1.8. 1.4. 1.2. 1.5. 1.8. 1.4. ANSWER DOWNLOAD EXAMIANS APP
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