Electrical Machines A 4-pole DC generator runs at 1500 rpm. The frequency of current in the armature winding is: 50 Hz. 25 Hz. Zero Hz. 100 Hz. 50 Hz. 25 Hz. Zero Hz. 100 Hz. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Stray losses in transformer occurs in transformer insulating oil. paper insulation in transformers. winding conductors and steel structures of transformer. steel core. transformer insulating oil. paper insulation in transformers. winding conductors and steel structures of transformer. steel core. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines DC motors are stopped by opening line switches and not by forcing the handle of the motor starter back to OFF position. This is due to occurance of Heavy sparking at brushes. Heavy sparking at the first stud of starting resistance steps. None of these. Both of above. Heavy sparking at brushes. Heavy sparking at the first stud of starting resistance steps. None of these. Both of above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines On what factors the speed of dc motor depends? Applied voltage. All of these. Field flux. Armature current Ia. Applied voltage. All of these. Field flux. Armature current Ia. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Two identical loss less series motors connected in series across a dc supply voltage, runs at speed of N1 and N2, then ratio of their output power is none. N12 : N22. 1 : 1. N1 : N2. none. N12 : N22. 1 : 1. N1 : N2. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A self-excited shunt generator fails to build up, because 1. the field circuit is open 2. The armature circuit is open 3. the residual magnetism is absent 4. The direction of rotation is wrong From these, the correct answer is 1, 3 1, 2, 3 and 4 1, 2 and 3 3 only 1, 3 1, 2, 3 and 4 1, 2 and 3 3 only ANSWER DOWNLOAD EXAMIANS APP
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