Electrical Machines Current in a coil undergoing commutation is not able to get reversed completely by the end of commutation period. It is due to coil resistance. reactance voltage induced in the coil. None of these armature emf. coil resistance. reactance voltage induced in the coil. None of these armature emf. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Winding conductors of an electrical power transformer are mainly insulated by cotton insulation. paper insulation. wooden insulation. rubber insulation. cotton insulation. paper insulation. wooden insulation. rubber insulation. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3-phase, 50 Hz, 4 pole induction motor is running at 1440 rpm. Find the rotor efficiency? 96% 94% 92% 95% 96% 94% 92% 95% 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 1, 4 1, 3, 5 2, 3 , 5 2, 4 ,5 1, 4 1, 3, 5 2, 3 , 5 2, 4 ,5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In 3 - Φ induction motor some times copper bars are placed deep in the rotor to improve starting torque. reduce copper loss. improve power factor. improve efficiency. improve starting torque. reduce copper loss. improve power factor. improve efficiency. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If input of a transformer is square wave the output will be square wave. sine wave. pulsed wave. triangular wave. square wave. sine wave. pulsed wave. triangular wave. ANSWER DOWNLOAD EXAMIANS APP
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