Electrical Machines The total core loss of a 400 V, 50 Hz transformer is 2400W, when it is supplied by 200 V, 25 Hz loss is 800W. Calculate eddy current loss and hysteresis loss? 800W, 1600W 1600W, 800W 1400W, 1000W 1000W , 1400W 800W, 1600W 1600W, 800W 1400W, 1000W 1000W , 1400W ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A dc shunt motor runs at a no-load speed of 1140 rpm. At full load, armature reaction weakens the main flux by 5% whereas the armature circuit voltage drops by 10%. The motor full-load speed in rpm is 1203 1200 1080 1000 1203 1200 1080 1000 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 200 V DC machine supplies 20 A at 200 V as a generator. The armature resistance is 0.2 Ω. If the machine is now operated as a motor at same terminal voltage and current but with the flux increased by 10%, the ratio of motor speed to generator speed is 0.87 0.96 0.95 1.06 0.87 0.96 0.95 1.06 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The noise resulting from vibrations of lamination set by magnetic forces, is termed as hum. magnetostriction. zoom. boo. hum. magnetostriction. zoom. boo. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements regarding dc machines : 1. possible resistance of shunt-field winding is 1 Ω 2. possible resistance of series-field winding is 1 Ω 3. electrographite brushes are used for 230 V, 10 A machines 4. Copper-graphite brushes are used for 230 V, 10 A machines 5. Possible armature-circuit resistance is 1 Ω From these, the correct statements are 1, 4 2, 3 , 5 1, 3, 5 2, 4 ,5 1, 4 2, 3 , 5 1, 3, 5 2, 4 ,5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In DC generators brushes are used for collecting of voltage reduce eddy current loss convert ac armature current in to dc collecting of current without any sparkings collecting of voltage reduce eddy current loss convert ac armature current in to dc collecting of current without any sparkings ANSWER DOWNLOAD EXAMIANS APP
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