Electrical Machines If peak value of phase mmf is F max , then peak value of the rotating field caused by three phase is (3/2)Fmax. (1/2)Fmax. Fmax. 3Fmax. (3/2)Fmax. (1/2)Fmax. Fmax. 3Fmax. 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, 4 2, 3 1, 3 1, 4 2, 4 2, 3 1, 3 1, 4 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 4 pole lap wound dc generator has 4 brushes, if one of the brush is damaged, what will be the change in V, I and P ratings V/2, I and P/2 V/2, I/2 and P/4 V, I and P V, I/2 and P/2 V/2, I and P/2 V/2, I/2 and P/4 V, I and P V, I/2 and P/2 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following induction motor has the highest starting torque? Same in both induction motors. Slip ring induction motor. Squirrel cage induction motor. None of these Same in both induction motors. Slip ring induction motor. Squirrel cage induction motor. None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For standing a DC motor a starter is required because it limits the starting current to a safe value. None of these it limits the speed of the motor. It starts the motor. it limits the starting current to a safe value. None of these it limits the speed of the motor. It starts the motor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A small air gap in poly phase induction motor helps to reduce chance of crawling. reduce magnetizing current. reduce chance of cogging. increase starting torque. reduce chance of crawling. reduce magnetizing current. reduce chance of cogging. increase starting torque. ANSWER DOWNLOAD EXAMIANS APP
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