Electrical Machines which of the following losses are negligible in blocked rotor test? iron loss mechanical loss copper loss both A and B iron loss mechanical loss copper loss both A and B 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, 2 and 4 1 and 3 2, 3 and 4 1, 2, and 3 1, 2 and 4 1 and 3 2, 3 and 4 1, 2, and 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following is/are the advantages of carbon brush over the copper brush? All of these In case of any sparking they will be less damaged than copper brushes They are not hard as copper brush They are self lubricating in nature All of these In case of any sparking they will be less damaged than copper brushes They are not hard as copper brush They are self lubricating in nature ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC series motor drawing an armature current of Ia is operating under saturated magnetic conditions. The torque developed in the motor is proportional to 1/Ia Ia I/Ia2 Ia2 1/Ia Ia I/Ia2 Ia2 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What will happen if the the supply terminals are reversed in case of a DC shunt motor? The motor will run at its normal speed in the same direction as before. The motor will run much faster in the same direction. The motor will stop. The motor will run in reverse direction. The motor will run at its normal speed in the same direction as before. The motor will run much faster in the same direction. The motor will stop. The motor will run in reverse direction. 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. increase remain the same. be unpredictable. decrease. increase remain the same. ANSWER DOWNLOAD EXAMIANS APP
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