Electrical Machines The brush-axis of a bipolar dc motor is rotated by 90°. The effect of this rotation on the back emf Eband the torque developed Tdwould be such that both Eb and Td are unchanged Eb is zero, but Td is unchanged Eb is unchanged, but Td is zero both Eb and Td are zero both Eb and Td are unchanged Eb is zero, but Td is unchanged Eb is unchanged, but Td is zero both Eb and Td are zero ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC series motor must started on no load because it would Run at dangerously high speed. Draw more current without producing sufficient torque. Fail to start without load. Not develop starting torque. Run at dangerously high speed. Draw more current without producing sufficient torque. Fail to start without load. Not develop starting torque. 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 If the temperature of armature resistance is increased, the speed of a series motor would not change. increase. None of above. decrease. not change. increase. None of above. decrease. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a transformer maximum flux density is not constant, the eddy current loss varies as f² f V V² f² f V V² ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines DC generator will not build up voltage if field resistance is more than critical resistance. due to wrong direction of rotation. if it has lost residual magnetism. any one of above. if field resistance is more than critical resistance. due to wrong direction of rotation. if it has lost residual magnetism. any one of above. ANSWER DOWNLOAD EXAMIANS APP
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