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 s2. f / s. sf / 2. sf. s2. f / s. sf / 2. sf. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Counter emf of a DC motor regulates its armature voltage. exceeds supply voltage aids applied voltage. helps in energy conversion. regulates its armature voltage. exceeds supply voltage aids applied voltage. helps in energy conversion. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The interpoles in dc machines have a tapering shape in order to economise on the material required for interpoles and their windings increase the acceleration of commutation reduce the overall weight reduce the saturation in the interpole economise on the material required for interpoles and their windings increase the acceleration of commutation reduce the overall weight reduce the saturation in the interpole ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The sparking at the the brushes, in a DC machines is due to high resistance of carbon brushes. reactance voltage. armature reaction. presence of commutator. high resistance of carbon brushes. reactance voltage. armature reaction. presence of commutator. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 220 V DC machine has an armature resistance 1Ω. If the full load current is 20 A, the difference of induced voltage and generator is 0 V. 20 V. 40 V. 60 V. 0 V. 20 V. 40 V. 60 V. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A compound dc generator is delivering full load current at a terminal voltage of 230 V. Its series-field winding gets short circuited. If its terminal voltage 1. becomes more than 230 V, it is overcompounded generator 2. becomes more than 230 V, it is differentially compounded generator 3. becomes less than 230 V, it is overcompounded generator 4. becomes less than 230 V, it is differentially compounded generator 5. becomes less than 230 V, it is level compounded generator From these, the correct answer is 2,3 1, 4 2, 3, 5 1, 4, 5 2,3 1, 4 2, 3, 5 1, 4, 5 ANSWER DOWNLOAD EXAMIANS APP
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