Electrical Machines Maximum allowable moisture content of power transformer insulating oil is generally taken as 25 ppm. 20 ppm. 35 ppm. 45 ppm. 25 ppm. 20 ppm. 35 ppm. 45 ppm. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Rotating magnetic field is produced in an induction motor because of either stator winding or rotor winding. stator winding. None of these rotor winding. either stator winding or rotor winding. stator winding. None of these rotor winding. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the armature electric current is increased to double its previous value, and the time of commutation is halved, how will the reactance voltage vary? It will be halved. It will be doubled. It will remain the same. It will becomes four times. It will be halved. It will be doubled. It will remain the same. It will becomes four times. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A transformer has hysteresis loss of 30 W, at 240 V, 60 Hz. The hysteresis loss at 200 V, 50 Hz will be 30 W. 28 W. 25 W. 36 W. 30 W. 28 W. 25 W. 36 W. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following is done in speed control of DC motor by field flux control? Inserting an additional resistance in the armature circuit. Inserting an additional resistance in the field circuit. Inserting resistance to armature circuit and field circuit. Any of above. Inserting an additional resistance in the armature circuit. Inserting an additional resistance in the field circuit. Inserting resistance to armature circuit and field circuit. Any of above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3-φ alternator has negligible stator resistance. A short circuit test is conducted on this alternator. At a particular speed, a field current of If1 is required to drive the rated armature current. If the speed of the alternator is reduced to half, the field current required to maintain rated armature current Would be equal to If1/2. Cannot be predicted due to insufficient data. Woud be equal to 2If1. Would be equal to If1. Would be equal to If1/2. Cannot be predicted due to insufficient data. Woud be equal to 2If1. Would be equal to If1. ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS