Electrical Machines An induction motor having 8 poles runs at 727.5 rpm. If the supply frequency is 50Hz, the emf in the rotor will have a frequency of 48.5Hz 1.5Hz 51.5Hz 2.5Hz 48.5Hz 1.5Hz 51.5Hz 2.5Hz ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements : For a level compounded dc generator to run at constant voltage, the series field mmf must effectively compensate 1. armature reaction mmf 2.armature resistance drop 3. brush contact voltage drop Which of these statements is/are correct ? 1, 2 and 3 1 and 3 2 alone 1 and 2 1, 2 and 3 1 and 3 2 alone 1 and 2 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The DC generator runs at a speed of 1000 rpm and flux per pole is 0.2 Wb, number of poles are 2 the winding is wave wound and having 480 conductors. The critical speed is 1200 rpm. Then the generated emf ( Eg ) 2000 Volt. 1600 Volt. 0 Volt. 1500 Volt. 2000 Volt. 1600 Volt. 0 Volt. 1500 Volt. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Motors for fans and pumps are selected in the rpm range 375 to 500. 500 to 720. 720 to 920. 1440 to 2880. 375 to 500. 500 to 720. 720 to 920. 1440 to 2880. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a synchronous machine, if the field flux axis is ahead of the armature field axis in the direction of rotation, the machine operating is synchronous motor. synchronous generator. asynchronous generator. asynchronous motor. synchronous motor. synchronous generator. asynchronous generator. asynchronous motor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 4 pole dynamo with wave wound armature has 51 slots contains 20 conductors in each slot. If induced emf 357 Volts and speed is 8500 rpm, flux per pole will be 1.4 mWb. 3.5 mWb. 2.7 mWb. 1.2 mWb. 1.4 mWb. 3.5 mWb. 2.7 mWb. 1.2 mWb. ANSWER DOWNLOAD EXAMIANS APP