Electrical Machines A 8-pole, DC generator has a simplex wave-wound armature containing 32 coils of 6 turns each. Its flux per pole is 0.06 Wb. The machine is running at 250 rpm. The induced armature voltage is 768 V 96 V 384 V 192 V 768 V 96 V 384 V 192 V 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 and 3 1, 2 and 3 2 alone 1 and 2 1 and 3 1, 2 and 3 2 alone 1 and 2 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In 3 - Φ induction motor some times copper bars are placed deep in the rotor to improve starting torque. improve power factor. improve efficiency. reduce copper loss. improve starting torque. improve power factor. improve efficiency. reduce copper loss. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In case the conditions for maximum power for DC motor are established, the efficiency of the motor will be Less than 50 % Any where between 75 % and 90 %. Around 100 %. Around 90 % Less than 50 % Any where between 75 % and 90 %. Around 100 %. Around 90 % ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a step down transformer which one of the following statements is true? Secondary power is less than primary power. Number of secondary turns is more than that of primary. Secondary current is less than primary current. Number of secondary turns is less than primary turns. Secondary power is less than primary power. Number of secondary turns is more than that of primary. Secondary current is less than primary current. Number of secondary turns is less than primary turns. 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