Electrical Machines In a lap winding dc machine number of conductors are 100 and number of parallel paths are 10. Find the average pitch 10 1 50 100 10 1 50 100 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature resistance of a permanent magnet dc motor is 0.8 Ohm. At no load, the motor draws 1.5 A from a supply voltage of 25 V and runs at 1500 rpm. The efficiency of the motor while it is operating on load at 1500 rpm drawing a current of 3.5 A from the same source will be 59.2%. 57.1%. 48.0%. 88.8%. 59.2%. 57.1%. 48.0%. 88.8%. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is the mechanical power developed by a DC series motor is maximum? Back emf is equal to applied voltage. None of above. Back emf is equal to zero. Back emf is equal to half the applied voltage. Back emf is equal to applied voltage. None of above. Back emf is equal to zero. Back emf is equal to half the applied voltage. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 250 volt dc series motor having an armature resistance of 0.2 Ω takes a load current of 60 A. What will be the torque produced at the shaft of the motor? Consider brush drop of 1V. 133.22 N-m can not be determined. 266.20 N-m. 234.76 N-m. 133.22 N-m can not be determined. 266.20 N-m. 234.76 N-m. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In star-delta starting of squirrel cage induction motor compared to DOL starting the starting current and torque are 1/√3, 1/√3 1/3, 1/√3 1/√3, 1/3 1/3, 1/3 1/√3, 1/√3 1/3, 1/√3 1/√3, 1/3 1/3, 1/3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature mmf in a dc machine is 1. stationary with respect to field poles 2. stationary with respect to armature 3. rotating with respect to field poles 4. rotating with respect to armature From these, the correct answer is 2, 3 1, 4 2, 4 1, 3 2, 3 1, 4 2, 4 1, 3 ANSWER DOWNLOAD EXAMIANS APP