Electrical Machines A load of 900 lbs is to be raised with a lift car weighting 855 lbs at a speed of 110 feet per minute, the over balance being 40 % and percentage efficiency 45 %. Find the horse power of the motor without counterweight 150. 180. 170. 160. 150. 180. 170. 160. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The introduction of interpoles in between the main poles improves the performance of a dc machine, because the interpoles produce additional flux to augment the developed torque the inequality of air-gap flux on the top and bottom halves of the armature is removed a counter-emf is induced in the coil undergoing commutation the flux waveform is improved with reduction in harmonics the interpoles produce additional flux to augment the developed torque the inequality of air-gap flux on the top and bottom halves of the armature is removed a counter-emf is induced in the coil undergoing commutation the flux waveform is improved with reduction in harmonics ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 200 V DC machine supplies 20 A at 200 V as a generator. The armature resistance is 0.2 Ω. If the machine is now operated as a motor at same terminal voltage and current but with the flux increased by 10%, the ratio of motor speed to generator speed is 0.95 0.87 1.06 0.96 0.95 0.87 1.06 0.96 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In dc machines, the field-flux axis and armature-mmf axis are respectively along direct axis and indirect axis quadrature axis and direct axis quadrature axis and interpolar axis direct axis and interpolar axis direct axis and indirect axis quadrature axis and direct axis quadrature axis and interpolar axis direct axis and interpolar axis ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Essential conditions for two DC generators are connecting for parallel operation is/are polarities should be same. both A and B. rating of generators should be same. terminal voltage should be same. polarities should be same. both A and B. rating of generators should be same. terminal voltage should be same. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 220 V, DC shunt motor is operating at a speed of 1440 rpm. The armature resistance is 1.0 Ω and armature current is 10 A. of the excitation of the machine is reduced by 10%, the extra resistance to be put in the armature circuit to maintain the same speed and torque will be 1.79 Ω 2 .1 Ω 3.1 Ω 1.8 9 Ω 1.79 Ω 2 .1 Ω 3.1 Ω 1.8 9 Ω ANSWER DOWNLOAD EXAMIANS APP
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