Electrical Machines Which of the following is done in speed control of DC motor by field flux control? Inserting an additional resistance in the field circuit. Any of above. Inserting resistance to armature circuit and field circuit. Inserting an additional resistance in the armature circuit. Inserting an additional resistance in the field circuit. Any of above. Inserting resistance to armature circuit and field circuit. Inserting an additional resistance in the armature circuit. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which type of motors are used for lathes? Either A or B. Synchronous motor. Cage induction motor. DC shunt motors. Either A or B. Synchronous motor. Cage induction motor. DC shunt motors. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For a transformer to be tested at full load conditions but consuming only losses from the main, we do None of these OC and SC tests back to back test load test None of these OC and SC tests back to back test load test 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. Woud be equal to 2If1. Would be equal to If1. Cannot be predicted due to insufficient data. Would be equal to If1/2. Woud be equal to 2If1. Would be equal to If1. Cannot be predicted due to insufficient data. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A commutator with a diameter of 50 cm rotating at 1000 rpm. For a brush width of 1.5 cm, find the time of commutation in ms. 0.573. 0.649. 0.512. 0.443. 0.573. 0.649. 0.512. 0.443. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When R2 is rotor resistance, X2 the rotor reactance at supply frequency and s the slip, then the condition for maximum torque under running condition will be R2 = sX2. R2 = s2X2. sR2 = X2. R2 = s2X2. R2 = sX2. R2 = s2X2. sR2 = X2. R2 = s2X2. ANSWER DOWNLOAD EXAMIANS APP