Electrical Machines If Pi and Pc represent core and full load copper loss respectively, the maximum KVA delivered to load corresponding to maximum efficiency is equal to rated KVA is (Pi/Pc)2 Pc/Pi Pi/Pc √(Pi/Pc) (Pi/Pc)2 Pc/Pi Pi/Pc √(Pi/Pc) ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In DC generators, the brushes remain in contact with conductors which there is no hard and fast rule for this. lie under north pole. lie under south pole. lie in the inter polar gaps. there is no hard and fast rule for this. lie under north pole. lie under south pole. lie in the inter polar gaps. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In large sized DC machines the compensating windings are provided to neutralize voltage induced in coil due to fluctuation of l reduce eddy current losses by providing local short circuits. compensate for the decrease in speed due to increase of load. None of these neutralize voltage induced in coil due to fluctuation of l reduce eddy current losses by providing local short circuits. compensate for the decrease in speed due to increase of load. None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A single-phase transformer has its maximum efficiency at 60 percent of full load. At full load copper loss will be equal to core loss. zero. more than core loss. less than core loss. equal to core loss. zero. more than core loss. less than core loss. 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 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 Eb is zero, but Td is unchanged both Eb and Td are unchanged ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The direction of generated emf in the armature coil of a DC machine is 1. the same as that of the current in a generator 2. the same as that of the current in a motor 3. opposite to that of the current in a generator 4. opposite to that of the current in a motor From these, the correct answer is 1, 4 1, 3 2, 3 2, 4 1, 4 1, 3 2, 3 2, 4 ANSWER DOWNLOAD EXAMIANS APP
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