Electrical Machines In a dc machine 72 number of coils are used. Find the number of commutator segments required? 74 36 72 37 74 36 72 37 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When the armature current of 5 Amp is flowing through the dc motor the torque produced is 47 Nm. Keeping the speed constant if the armature current is increased to 7 amp, calculate the new torque. Assume losses to be constant. 27.73 Nm . 38.5 Nm. 74 Nm. 65.8 Nm. 27.73 Nm . 38.5 Nm. 74 Nm. 65.8 Nm. 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 3, 4, 5 1, 2, 5 2, 3, 6 2, 4, 5, 6 3, 4, 5 1, 2, 5 2, 3, 6 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For larger units high torque it is preferred to use Slip induction motor. Universal motor. Partial motor. DC shunt motor. Slip induction motor. Universal motor. Partial motor. DC shunt motor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the excitation is reduced, the power factor is unity power factor leading power factor lagging power factor None of these unity power factor leading power factor lagging power factor None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements: To control the speed of a dc shunt motor above the base speed over a reasonably wide range, the motor must 1. have compensating winding 2. have interpole winding 3. be started using a 3-point starter 4. be started using a 4-point starter Of these statements 1, 2 and 4 are correct 1 and 3 are correct 1, 2 and 3 are correct 2 and 4 are correct 1, 2 and 4 are correct 1 and 3 are correct 1, 2 and 3 are correct 2 and 4 are correct ANSWER DOWNLOAD EXAMIANS APP
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