Electrical Machines Which of the following is/are the advantages of carbon brush over the copper brush? In case of any sparking they will be less damaged than copper brushes They are self lubricating in nature They are not hard as copper brush All of these In case of any sparking they will be less damaged than copper brushes They are self lubricating in nature They are not hard as copper brush All of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 220 V dc machine has an armature resistance of 1Ω.If the full-load current is 20 A, the differenc in the induced voltages when the machine is running as a motor and as a generator is 20 V 50 V zero 40 V 20 V 50 V zero 40 V ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For a given torque, reducing diverter resistance of a DC series motor causes decrease in speed demanding less armature current. increase in speed demanding more armature current. increase in speed but armature currnet remains the same. decrease in speed but armature current remains the same. decrease in speed demanding less armature current. increase in speed demanding more armature current. increase in speed but armature currnet remains the same. decrease in speed but armature current remains the same. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In an induction motor, what is the ratio of rotor input to rotor copper loss? 1/(1-S) 1/S S 1-S 1/(1-S) 1/S S 1-S ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines From no load to full load the slip will slightly decrease. not change. None of these slightly increase. slightly decrease. not change. None of these slightly increase. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Ward-Leonard system for controlling the speed of a DC motor is used where All of above. Very fine speed control over the whole range from zero to normal speed is required. The accuracy in speed control is required. The speed in both the direction is required. All of above. Very fine speed control over the whole range from zero to normal speed is required. The accuracy in speed control is required. The speed in both the direction is required. ANSWER DOWNLOAD EXAMIANS APP
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