Electrical Machines Find the number of poles required, when the frequency is 50Hz and speed of the motor is 500 rpm? 12 24 5 10 12 24 5 10 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3-phase, alternator has generated emf per phase of 230 V with 10% 3rd harmonic and 6% 5th harmonic content. Calculate rms line voltage for star connection. 50 V. 399 V. 100 V. 230.2 V. 50 V. 399 V. 100 V. 230.2 V. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In synchronous generator a synchronous dead load (lamp, furnaces etc) has no ____________ hence it has no natural frequency of oscillation. restoring torque. damping torque. synchronizing power co efficient. mechanical rotatory system. restoring torque. damping torque. synchronizing power co efficient. mechanical rotatory system. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The magnetic circuit of a dc shunt generator with negligible armature resistance and brush contact voltage drop remains unsaturated when it delivers full-load current at rated terminal voltage. The brushes are kept in the interpolar axis and speed is maintained constant. When the load is switched off, the terminal voltage would become zero increase remain the same decrease become zero increase remain the same decrease ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The direction of generated emf in the armature coil of a DC machine is 1. the same as that of the current in a generator 2. the same as that of the current in a motor 3. opposite to that of the current in a generator 4. opposite to that of the current in a motor From these, the correct answer is 1, 3 2, 3 2, 4 1, 4 1, 3 2, 3 2, 4 1, 4 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 rotate in the same direction as before maintenance. get heated and damaged. not start at all. rotate in direction opposite to that before maintenance. rotate in the same direction as before maintenance. get heated and damaged. not start at all. rotate in direction opposite to that before maintenance. ANSWER DOWNLOAD EXAMIANS APP