Electrical Machines Iron losses in a DC machine are independent of variation in speed. voltage. load. speed and voltage. speed. voltage. load. speed and voltage. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines An induction motor is, in general analogous to two winding transformer with secondary open circuited. None of these two winding transformer with secondary short circuited. auto transformer. two winding transformer with secondary open circuited. None of these two winding transformer with secondary short circuited. auto transformer. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If s is the slip and f is the supply frequency of an induction motor, the frequency of rotor current is given by f / s. sf / 2. s2. sf. f / s. sf / 2. s2. sf. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following represents the commutator pitch? Number of conductors spanned by one coil at the front end of the armature. The distance between the staring of first coil and its next successive coil Number of conductors spanned by one coil at the back end of the armature. Number of commutator segments between two successive coils. Number of conductors spanned by one coil at the front end of the armature. The distance between the staring of first coil and its next successive coil Number of conductors spanned by one coil at the back end of the armature. Number of commutator segments between two successive coils. ANSWER DOWNLOAD EXAMIANS APP
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 Eb is zero, but Td is unchanged both Eb and Td are unchanged both Eb and Td are zero Eb is unchanged, but Td is zero Eb is zero, but Td is unchanged both Eb and Td are unchanged both Eb and Td are zero Eb is unchanged, but Td is zero ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A self-excited shunt generator fails to build up, because 1. the field circuit is open 2. The armature circuit is open 3. the residual magnetism is absent 4. The direction of rotation is wrong From these, the correct answer is 1, 2 and 3 3 only 1, 3 1, 2, 3 and 4 1, 2 and 3 3 only 1, 3 1, 2, 3 and 4 ANSWER DOWNLOAD EXAMIANS APP
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