Electrical Machines What is the increase in the torque expressed as percentage of initial torque, if current drawn by the dc series motor is increased from 10A to 11A? 10% 41% 21% 11% 10% 41% 21% 11% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC Shunt Motor having shunt field resistance of 250 Ω and armature resistance of 0.5 Ω is connected to 250 V supply and load current of 21 A. What is the back emf generated ? 150 V. 230 V. 210 V 240 V. 150 V. 230 V. 210 V 240 V. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A generator may loose residual magnetism due to over excitation. heating. any of these. vibrations. over excitation. heating. any of these. vibrations. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC Shunt Motor if the load current increases keeping the terminal voltage constant, then flux will any of the above. decrease. remain constant. increase. any of the above. decrease. remain constant. increase. 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 3, 4, 5 2, 4, 5, 6 2, 3, 6 1, 2, 5 3, 4, 5 2, 4, 5, 6 2, 3, 6 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In case of induction motors the ratio of length to pole pitch for minimum cost, is taken as 1.5 to 2. 2 to 3. 3 to 5. 1.0. 1.5 to 2. 2 to 3. 3 to 5. 1.0. ANSWER DOWNLOAD EXAMIANS APP
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