Electrical Machines The magnetic field which initially induces emf in the armature in a self excited DC generator is because of armature reaction. residual magnetism. permanent magnets. None of these armature reaction. residual magnetism. permanent magnets. None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The voltmeter connected across a generator reads voltage same at no load and at full load (rated). The generator is of the type short - shunt generator. level compound. series generator. shunt generator. short - shunt generator. level compound. series generator. shunt generator. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3-phase, 50 Hz, 4 pole induction motor is running at 1440 rpm and rotor input power is 2KW. Find the rotor copper loss? 80W 100W 40W 60W 80W 100W 40W 60W ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a 3-phase induction motor, if the supply voltage and frequency are reduced by the same ratio, then slip at which maximum torque occurs is less and maximum torque decreases more and maximum torque remains constant more and maximum torque decreases less and maximum torque increases less and maximum torque decreases more and maximum torque remains constant more and maximum torque decreases less and maximum torque increases ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following represents the commutator pitch? 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. 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. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements : Interpoles in dc machines 1. reducearmature reaction effects in the interpolar region 2. have the same dimension as main polls 3. have their windings connected in series with the armature 4. have same number of turns as the armature 5. have the polarity same as that of the main pole ahead in a motor From these, the correct statements are 1, 2, 3 and 5 1, 2 and 3 1, 3 and 5 1 and 3 1, 2, 3 and 5 1, 2 and 3 1, 3 and 5 1 and 3 ANSWER DOWNLOAD EXAMIANS APP