Electrical Machines The residual magnetism of a self-excited dc generator is lost. To build up its emf again field winding must be excited by low voltage dc supply the field winding connection must be reversed the armature connection must be reversed the field winding must be replaced field winding must be excited by low voltage dc supply the field winding connection must be reversed the armature connection must be reversed the field winding must be replaced ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Eb/Vt ratio of a DC motor is an indication of starting torque. speed regulation. running torque. efficiency. starting torque. speed regulation. running torque. efficiency. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Interpoles in a DC motor must be Shunt excited and should have the same polarity as that of the behind main pole in the direction of rotation of armature. Series excited and should have the same polarity as that of the ahead main pole in the direction of rotation of armature. Series excited and should have the same polarity as that of the behind main pole in the direction of rotation of armature. Shunt excited and should have the same polarity as that of the ahead main pole in the direction of rotation of armature. Shunt excited and should have the same polarity as that of the behind main pole in the direction of rotation of armature. Series excited and should have the same polarity as that of the ahead main pole in the direction of rotation of armature. Series excited and should have the same polarity as that of the behind main pole in the direction of rotation of armature. Shunt excited and should have the same polarity as that of the ahead main pole in the direction of rotation of armature. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Two transformers with identical rating, are designed with flux densities of 1.2 and 1.4 Wb / m2 respectively. The weight of first transformer per kVA is more than that of second transformer. equal to that of second transformer. none of these. less than that of second transformer. more than that of second transformer. equal to that of second transformer. none of these. less than that of second transformer. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Slip rings of an induction motors are made of stainless steel. phosphor bronze. carbon. aluminium. stainless steel. phosphor bronze. carbon. aluminium. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A large series motor is never started without some mechanical on it because otherwise it will Produce sparking at brushes. Open fuse or circuit breaker. Develop excessive speed and damage itself. Draw too much current. Produce sparking at brushes. Open fuse or circuit breaker. Develop excessive speed and damage itself. Draw too much current. ANSWER DOWNLOAD EXAMIANS APP
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