Electrical Machines The frequency of voltage generated by an alternator having 8 poles and rotating at 250 rpm is 16.67 Hz. 25 Hz. 60 Hz. 50 Hz. 16.67 Hz. 25 Hz. 60 Hz. 50 Hz. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines R1 is the resistance of the primary winding of the transformer. The turn ratio in terms of primary to secondary is K. Then the equivalent resistance of the primary referred to secondary is K²R1 K×R1 R1 /K² R1 /K K²R1 K×R1 R1 /K² R1 /K ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Tap changer is generally provided in current transformer. power transformer. earthing transformer. voltage transformer. current transformer. power transformer. earthing transformer. voltage transformer. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines To get the speed of DC motor more than normal without wastage of electrical energy _____________ is used. Ward Leonard control. rheostatic control. none of above. any of above method. Ward Leonard control. rheostatic control. none of above. any of above method. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Two of supply terminals to a 3 - Φ induction motor get interchanged during re-connection after normal maintenance. When switched on the supply, the motor will get heated and damaged. rotate in the same direction as before maintenance. not start at all. rotate in direction opposite to that before maintenance. get heated and damaged. rotate in the same direction as before maintenance. not start at all. rotate in direction opposite to that before maintenance. 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, 4, 6 1, 2, 6 1, 2, 5 1, 3, 5 1, 4, 6 1, 2, 6 1, 2, 5 1, 3, 5 ANSWER DOWNLOAD EXAMIANS APP
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