Electrical Machines In case of induction motors the ratio of length to pole pitch for minimum cost, is taken as 1.5 to 2. 1.0. 3 to 5. 2 to 3. 1.5 to 2. 1.0. 3 to 5. 2 to 3. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The direction of generated emf in the armature coil of a DC machine is 1. the same as that of the current in a generator 2. the same as that of the current in a motor 3. opposite to that of the current in a generator 4. opposite to that of the current in a motor From these, the correct answer is 2, 4 1, 4 1, 3 2, 3 2, 4 1, 4 1, 3 2, 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements regarding the speed control of dc motors : 1. ward-leonard method is suitable forconstant-torque drives 2. Ward-leonard method is suitable for constant-power drives 3. field-control method facilitates speed control below base speed 4. Armature-resistance control method is more efficient than ward-leanard method 5. Field-control method is suitable for constant-torque drives 6. Armature-resistance control method is suitable for constant-torque drives From these, the correct answer is 1, 2, 5 1, 2, 6 1, 3, 5 1, 4, 6 1, 2, 5 1, 2, 6 1, 3, 5 1, 4, 6 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following is/are the advantages of carbon brush over the copper brush? In case of any sparking they will be less damaged than copper brushes They are self lubricating in nature They are not hard as copper brush All of these In case of any sparking they will be less damaged than copper brushes They are self lubricating in nature They are not hard as copper brush All of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following is/are the methods to reduce the armature reaction and its effects? pole stacking compensating winding pole chamfering All of these pole stacking compensating winding pole chamfering All of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature resistance of the dc motor is generally of the range 0.1 ohm. 50 ohm. 0.5 ohm. 100 ohm. 0.1 ohm. 50 ohm. 0.5 ohm. 100 ohm. ANSWER DOWNLOAD EXAMIANS APP