Electrical Machines A 4 pole DC generator runs at 750 rpm and generate an emf of 240 V. The armature is wave wound and has 792 conductors. If the total flux from each pole is 0.0145 Wb. What is the leakage co-efficient? 1.8. 1.5. 1.2. 1.4. 1.8. 1.5. 1.2. 1.4. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For a specific open-circuit voltage of a DC generator, the short-circuit electric current will be maximum when it is separately excited. shunt connected. cumulatively compounded. differentially compounded. separately excited. shunt connected. cumulatively compounded. differentially compounded. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines An IM cannot run at synchronous speed because air friction will prevent it. induction motor will become synchronous motor. rotor torque will not be produced. none of above. air friction will prevent it. induction motor will become synchronous motor. rotor torque will not be produced. none of above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A dc shunt generator, when driven without any excitation, showed an open circuit voltage of 12 V. When the field winding was excited, the voltage dropped to zero. It happened because there was no residual magnetism in the field circuit there was a break in the armature circuit field resistance was higher than critical resistance field winding was wrongly connected there was no residual magnetism in the field circuit there was a break in the armature circuit field resistance was higher than critical resistance field winding was wrongly connected ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The damper windings also called the squirrel cage windings or damper grids consists of short-circuited copper bars embedded in the field pole faces. are provided on the stator for improving power factor. are provided in a synchronous motor to make it self starting. both (A) and (B). consists of short-circuited copper bars embedded in the field pole faces. are provided on the stator for improving power factor. are provided in a synchronous motor to make it self starting. both (A) and (B). ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A smaller air gap in a polyphase induction motor helps to reduce the magnetizing current. reduce the chance of crawling. increase the starting torque. reduce the chance of cogging. reduce the magnetizing current. reduce the chance of crawling. increase the starting torque. reduce the chance of cogging. ANSWER DOWNLOAD EXAMIANS APP
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