Electrical Machines Autotransformer makes effective saving on copper and copper losses, when its transformation ratio is equal to greater than one. very low less than one. approx to one. greater than one. very low less than one. approx to one. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In case of a dc motor the ratio Eb / E is indicative of ratio of starting to running torque. ratio of input to output voltage. ratio of starting to running current. efficiency. ratio of starting to running torque. ratio of input to output voltage. ratio of starting to running current. efficiency. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the excitation is critical, the power factor of the alternator is unity power factor. lagging power factor. leading power factor. None of these unity power factor. lagging power factor. leading power factor. None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 4 pole lap wound dc generator has 4 brushes, if one of the brush is damaged, what will be the change in V, I and P ratings V/2, I and P/2 V/2, I/2 and P/4 V, I and P V, I/2 and P/2 V/2, I and P/2 V/2, I/2 and P/4 V, I and P V, I/2 and P/2 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements regarding the speed control of dc motors : 1. ward-leonard method is suitable forconstant-torque drives 2. Ward-leonard method is suitable for constant-power drives 3. field-control method facilitates speed control below base speed 4. Armature-resistance control method is more efficient than ward-leanard method 5. Field-control method is suitable for constant-torque drives 6. Armature-resistance control method is suitable for constant-torque drives From these, the correct answer is 1, 4, 6 1, 3, 5 1, 2, 5 1, 2, 6 1, 4, 6 1, 3, 5 1, 2, 5 1, 2, 6 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Cogging and crawling are phenomena associated with cage induction machines and they are essentially the same. the former at a fraction of its rate speed and the latter during starting. the former during starting and the latter at a fraction of its rated speed. any of the above. cage induction machines and they are essentially the same. the former at a fraction of its rate speed and the latter during starting. the former during starting and the latter at a fraction of its rated speed. any of the above. ANSWER DOWNLOAD EXAMIANS APP
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