Electrical Machines To achieve spark less commutation brushes of DC generator are rocked ahead so as to bring them just ahead of magnetic neutral axis. None of these in magnetic neutral axis. just behind the magnetic neutral axis. just ahead of magnetic neutral axis. None of these in magnetic neutral axis. just behind the magnetic neutral axis. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Rotating magnetic field is produced in an induction motor because of rotor winding. either stator winding or rotor winding. stator winding. None of these rotor winding. either stator winding or rotor winding. stator winding. None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines As compared to an induction motor, the air gap in a DC motor is less than 50%. same. more. between 50% and 90%. less than 50%. same. more. between 50% and 90%. 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 2, 4 ,5 2, 3 , 5 1, 3, 5 1, 4 2, 4 ,5 2, 3 , 5 1, 3, 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements : 1. interpole windings are connected in series with armature windings 2. polarity of interpoles must be the same as that of the main poles in advance 3. distortion of the main field under the pole shoes is not affected by the use of interpoles From above, the correct answer is 1 alone 1 and 3 2 and 3 1 and 2 1 alone 1 and 3 2 and 3 1 and 2 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is the speed of stator rotating magnetic field with respect to rotor rotating magnetic field? Zero None of these Synchronous speed Slip speed Zero None of these Synchronous speed Slip speed ANSWER DOWNLOAD EXAMIANS APP
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