Electrical Machines Maximum allowable acidity level of power transformer insulating oil is generally taken as 0.5 mg of KOH / gm. 1 mg of KOH / gm. 2 mg of KOH / gm. 0.3 mg of KOH / gm. 0.5 mg of KOH / gm. 1 mg of KOH / gm. 2 mg of KOH / gm. 0.3 mg of KOH / gm. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature shaft must be able to with stand Twisting stains due to transmission of torque. Bending moment due to weight of the armature. All of these Any unbalanced magnetic pull on the armature core. Twisting stains due to transmission of torque. Bending moment due to weight of the armature. All of these Any unbalanced magnetic pull on the armature core. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Commutator pitches of duplex and simplex lap windings are respectively 4 ang 1 4 and 2 2 and 2 2 and 1 4 ang 1 4 and 2 2 and 2 2 and 1 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In dc machines, the field system has to be provided on stator unlike synchronous machines Where in it could be on any member, because commutator action is not possible otherwise it gives more uniform air-gap flux distribution dc machines are comparatively low rating machines. it reduces field structure iron losses commutator action is not possible otherwise it gives more uniform air-gap flux distribution dc machines are comparatively low rating machines. it reduces field structure iron losses ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The counter (or back) emf in a dc machine is 1. the same as generated emf in a dc motor 2. proportional to field flux and armature speed 3. not the same as generated emf in a dc motor 4.inversely proportional to field flux 5. proportional to number of armature conductors 6. constant from no load to full load From these, the correct answer is 2, 4, 5, 6 2, 3, 6 1, 2, 5 3, 4, 5 2, 4, 5, 6 2, 3, 6 1, 2, 5 3, 4, 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In the V curve shown in figure below for a synchronous motor, the parameter of Y and X coordinates are, respectively Armature current and field current. Torque and field current. Power factor and field current. Armature current and torque. Armature current and field current. Torque and field current. Power factor and field current. Armature current and torque. ANSWER DOWNLOAD EXAMIANS APP
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