Electrical Machines The material used for commutator brushes is mostly copper. carbon. cast iron. mica. copper. carbon. cast iron. mica. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The basic function of a transformer is to change the power factor the level of the voltage the power level the frequency the power factor the level of the voltage the power level the frequency ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the load current and flux of a DC motor are held constant and voltage applied across it armature is increased by 5%, the speed of the motor will Reduce by 5%. Remain unchanged. Depends on other factor. Increase by 5%. Reduce by 5%. Remain unchanged. Depends on other factor. Increase by 5%. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A Shunt generator running at 1000 rpm has generated emf of 100 V. If the speed increases to 1200 rpm, the generated emf will be nearly 240 V 175 V 120 V 140 V 240 V 175 V 120 V 140 V ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines To have sparkless commutation, the armature reaction effect in a DC machine is neutralized by compensating winding and commutating poles. shifting the brush axis from GNA to MNA. increasing field excitation. fixing the brush axis inline with the pole axis. compensating winding and commutating poles. shifting the brush axis from GNA to MNA. increasing field excitation. fixing the brush axis inline with the pole axis. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In V/f speed control of 3-phase induction motor, with increase in frequency, the slip at which maximum torque occurs None of these decrease. either of these. increase. None of these decrease. either of these. increase. ANSWER DOWNLOAD EXAMIANS APP