Electrical Machines In an induction motor, what is the ratio of rotor input to rotor copper loss? S 1/(1-S) 1-S 1/S S 1/(1-S) 1-S 1/S ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines To have sparkless commutation, the armature reaction effect in a DC machine is neutralized by fixing the brush axis inline with the pole axis. increasing field excitation. compensating winding and commutating poles. shifting the brush axis from GNA to MNA. fixing the brush axis inline with the pole axis. increasing field excitation. compensating winding and commutating poles. shifting the brush axis from GNA to MNA. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Induction motors normally use cast aluminium rotor because aluminium is easy to cast owing to its low melting point and is easily available. lighter in weight. cheaper in cost. of low resistivity. easy to cast owing to its low melting point and is easily available. lighter in weight. cheaper in cost. of low resistivity. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements regarding dc machines : 1. possible resistance of shunt-field winding is 1 Ω 2. possible resistance of series-field winding is 1 Ω 3. electrographite brushes are used for 230 V, 10 A machines 4. Copper-graphite brushes are used for 230 V, 10 A machines 5. Possible armature-circuit resistance is 1 Ω From these, the correct statements are 2, 4 ,5 1, 3, 5 1, 4 2, 3 , 5 2, 4 ,5 1, 3, 5 1, 4 2, 3 , 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When operating, two or more transformers in parallel, % impedance of these transformers should be inversely proportional to MVA rating of transformers. such that actual impedance of all transformers would be same. same. proportionate to MVA rating of transformers. inversely proportional to MVA rating of transformers. such that actual impedance of all transformers would be same. same. proportionate to MVA rating of transformers. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Under which of the following conditions hunting of synchronous motor is likely to occur ? Periodic variation of load. Over-excitation. Over-loading for long period. Small and constant load. Periodic variation of load. Over-excitation. Over-loading for long period. Small and constant load. ANSWER DOWNLOAD EXAMIANS APP
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