Electrical Machines In case of a dc motor the ratio Eb / E is indicative of efficiency. ratio of input to output voltage. ratio of starting to running torque. ratio of starting to running current. efficiency. ratio of input to output voltage. ratio of starting to running torque. ratio of starting to running current. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is the mechanical power developed by a DC series motor is maximum? Back emf is equal to half the applied voltage. None of above. Back emf is equal to applied voltage. Back emf is equal to zero. Back emf is equal to half the applied voltage. None of above. Back emf is equal to applied voltage. Back emf is equal to zero. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For a given torque, reducing divertor resistance of a DC series motor Increase in speed demanding more armature current. Decrease in speed but armature current remains the same. Decrease in speed demanding less armature current. Increase in speed but armature currnet remains the same. Increase in speed demanding more armature current. Decrease in speed but armature current remains the same. Decrease in speed demanding less armature current. Increase in speed but armature currnet remains the same. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Breather is provided in a transformer to absorb moisture from air entering in transformer. absorb moisture of air during breathing. filter the transformer oil. provide cold air in transformer. absorb moisture from air entering in transformer. absorb moisture of air during breathing. filter the transformer oil. provide cold air in transformer. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3-phase 6 pole 50 Hz induction motor is running at 5% slip.What is the speed of the motor? 900 rpm 1000 rpm 950 rpm 850 rpm 900 rpm 1000 rpm 950 rpm 850 rpm ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3-phase slip ring induction motor is wound for 4 poles on stator and 6 poles on the rotor. When 3-phase balanced voltage source at 50 Hz is applied, it will run at 750rpm 1000 rpm 1500 rpm zero speed 750rpm 1000 rpm 1500 rpm zero speed ANSWER DOWNLOAD EXAMIANS APP
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