Electrical Machines To get the speed of DC motor more than normal without wastage of electrical energy _____________ is used. rheostatic control. Ward Leonard control. any of above method. none of above. rheostatic control. Ward Leonard control. any of above method. none of above. 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 1, 2, 5 2, 4, 5, 6 3, 4, 5 2, 3, 6 1, 2, 5 2, 4, 5, 6 3, 4, 5 2, 3, 6 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Dummy coils are used for reducing armature reaction. mechanical balancing. All of these increasing efficiency. reducing armature reaction. mechanical balancing. All of these increasing efficiency. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If dimension of all the parts of a synchorous generator and the number of field and armature turns are double, then generated voltage will change by a factor of 4. 2. 1. 8. 4. 2. 1. 8. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC generator in case the brushes are moved so as to bring them in magnetic neutral axis, then, there will be demagnetisation. none of above. cross-magnetization as well as demagnetization. cross-magnetisation. demagnetisation. none of above. cross-magnetization as well as demagnetization. cross-magnetisation. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC series motor is running with a divertor connected across its field winding. If the divertor resistance is reduced then the speed of the motor will decrease. remain unaltered. become execessively high. increase. decrease. remain unaltered. become execessively high. increase. ANSWER DOWNLOAD EXAMIANS APP
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