Electrical Machines A 3 - Φ, 6 pole, 50 Hz IM is running at a full load speed of 980 rpm. If it delivers an air gap power of 98000 Watt, calculate the rotor ohmic loss? 1800 Watt. 1960 Watt. 980 Watt. 1920 Watt. 1800 Watt. 1960 Watt. 980 Watt. 1920 Watt. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The flux is maximum in the following part of a DC motor: pole core. under the interpole. under trailing pole tip. under leading pole tip. pole core. under the interpole. under trailing pole tip. under leading pole tip. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines To eliminate the 5th harmonic in the induced voltages their respective pitch factor angle should be 36° 72° 30° 18° 36° 72° 30° 18° ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In dc machines, 1. reactance voltage is proportional to armature current 2.reactance voltage is proportional to core length 3.reactance voltage is due to self-flux of the coil undergoing commutation 4. armature-cross flux is neutralized by interpolar flux 5. interpolarmmf is more than armature mmf in the interpolar zone From these, the correct answer is 2, 3, 4 1, 2, 5 1, 2, 3, 4 1, 3, 5 2, 3, 4 1, 2, 5 1, 2, 3, 4 1, 3, 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3 - Φ induction motor draws an current of 50 A from mains when starts by direct switching. If an auto transformer with 60 % tapping is used for starting the current drawn from the mains will be 50. 36. 80. 18. 50. 36. 80. 18. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines It is advisable to start a DC series motor with some load to Avoid sparking. Limit the current. Limit the flux. Limit the speed. Avoid sparking. Limit the current. Limit the flux. Limit the speed. ANSWER DOWNLOAD EXAMIANS APP