Electrical Engineering Answers

What is the function of the cylinder rotor? 

A 1100 V ,50 Hz, delta connected induction motor has a star connected slip ring rotor with a phase transformation ratio of 3.8. The rotor resistance and standstill leakage reactance are 0.012 Ω/phase and 0.25 Ω/phase respectively. Neglecting the stator impedance and magnetising current determine the rotor current at 4 % slip with slip rings shorted

A 150 KW ,3000 v, 50 Hz, 6-pole-star-connected induction motor has a start connected slip-ring with a transformation ratio of 3.6 (stator/rotor). The rotor resistance is 0.2 Ω/phase and its per phase/leakage reactance is 14.7 Ω/phase. The stator impedance may be neglected. Find the starting current and starting torque at rated voltage with short circuited slip–ring. 

A three phase induction motor is wound for 4 poles and is supplied from 50 Hz system. Calculate the rotor frequency when the rotor runs at 600 r.p.m. 

The stator of a three phase induction motor operates from a supply whose frequency is 50 Hz. Calculate the number of stator poles and total number of slots 1n the stator.

A 12 pole, 3-phase alternator drives at a speed of 500 r.p.m supplies power to an 8 pole, three-phase induction motor. If the slip of the motor at full load speed is 4 %, calculate the full load of the motor. 

A 12 pole, 3-phase alternator drives at a speed of 500 r.p.m supplies power to an 8 pole, three-phase induction motor. If the slip of the motor at full load speed is 4 %, calculate the full load of the motor. 

A 1.5 MVA ,3.3 kV, 40 pole, three-phase star connected asynchronous alternator has reactance of Xd = 4.01Ω/phase and Xq = 2.88Ω/phase.For a lagging power factor of 0.8 when delivering full load. Calculate a developed power: 

A circuit of 500 V for single-phase asynchronous motor has synchronous impedance of 3.2 Ω. The armature resistance is 0.3 Ω. Determine the induced emf if the machine develops 31.3 kW and the mechanical losses equals 4 kW

A synchronous motor has an equivalent armature reactance of 3.3 Ω.The field current is adjusted so that the induced emf is 950V. If the motor is taking 80 Kw from the supply at 800V, determine the power factor at which the machine operates.