Electrical Machines If the mechanical angle α between the stator and rotor poles increases, then the stator current Remains unchanged. Decreases. None of above. Increases. Remains unchanged. Decreases. None of above. Increases. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC generator, if P be the number of poles and N be the rpm of the rotor, then frequency of magnetic reversals will be PN/2. PN/60. PN/3000. PN/120. PN/2. PN/60. PN/3000. PN/120. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 220 V dc machine has an armature resistance of 1Ω.If the full-load current is 20 A, the differenc in the induced voltages when the machine is running as a motor and as a generator is zero 50 V 20 V 40 V zero 50 V 20 V 40 V ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In case of a dc motor the ratio Eb / E is indicative of efficiency. ratio of input to output voltage. ratio of starting to running torque. ratio of starting to running current. efficiency. ratio of input to output voltage. ratio of starting to running torque. ratio of starting to running current. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Where the shunt generators are widely used? Where the load is very high. Where voltage variation is needed over a wide load range. Where often load fluctuation is occurred. Where a constant voltage is required over a narrow load range. Where the load is very high. Where voltage variation is needed over a wide load range. Where often load fluctuation is occurred. Where a constant voltage is required over a narrow load range. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The introduction of interpoles in between the main poles improves the performance of a dc machine, because the interpoles produce additional flux to augment the developed torque the flux waveform is improved with reduction in harmonics a counter-emf is induced in the coil undergoing commutation the inequality of air-gap flux on the top and bottom halves of the armature is removed the interpoles produce additional flux to augment the developed torque the flux waveform is improved with reduction in harmonics a counter-emf is induced in the coil undergoing commutation the inequality of air-gap flux on the top and bottom halves of the armature is removed ANSWER DOWNLOAD EXAMIANS APP
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