Electrical Machines Which of the following transformer insulating oil generally used in India? Naphtha based insulating oil. Aromatics based insulating oil. Paraffin based insulating oil. Olefin based insulating oil. Naphtha based insulating oil. Aromatics based insulating oil. Paraffin based insulating oil. Olefin based insulating oil. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When the mechanical power is developed by a DC motor maximum Back emf is equal. back emf is equal to applied voltage. Back emf is equal to half of applied voltage. None of above. Back emf is equal. back emf is equal to applied voltage. Back emf is equal to half of applied voltage. None of above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The principle of operation of a 3 - Φ induction motor is almost similar to that of transformer with secondary short circuited. synchronous motor. repulsion start induction motor. capacitor start induction motor. transformer with secondary short circuited. synchronous motor. repulsion start induction motor. capacitor start induction motor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC series motor must started on no load because it would Not develop starting torque. Run at dangerously high speed. Draw more current without producing sufficient torque. Fail to start without load. Not develop starting torque. Run at dangerously high speed. Draw more current without producing sufficient torque. Fail to start without load. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature MMF waveform of a DC machine is pulsating. triangular. rectangular. sinusoidal. pulsating. triangular. rectangular. sinusoidal. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines To eliminate the 5th harmonic in the induced voltages their respective pitch factor angle should be 30° 18° 36° 72° 30° 18° 36° 72° ANSWER DOWNLOAD EXAMIANS APP