The figure below shows the per-phase Open Circuit Characteristics (measured in V) and Short Circuit Characteristics (measured in A) of a 14 kVA, 400~V. 50~Hz, 4-pole, 3-phase, delta connected alternator, driven at 1500 rpm. The field current, If is measured in A. Readings taken are marked as respective (x, y) coordinates in the figure. Ratio of the unsaturated and saturated synchronous impedances  of the alternator is closest to

A 20-pole alternator is having 180 identical stator slots with 6 conductors in each slot. All the coils of a phase are in series. If the coils are connected to realize single-phase winding, the generated voltage is . If the coils are reconnected to realize three-phase star-connected winding, the generated phase voltage is .

Assuming full pitch, single-layer winding, the ratio  is

Distributed winding and short chording employed in AC machines will result in

A synchronous generator is feeding a zero power factor (lagging) load at rated current.  The armature reaction is

A 4 pole, 50 Hz synchronous generator has 48 slots in which a double layer winding is housed.  Each coil has 10 turns and is short pitched by an angle to 36° electrical.  The fundamental flux per pole is 0.025Wb.

The line-to-line induced EMF (in volts). For a three phase star connection is approximately

A 4 pole, 50 Hz synchronous generator has 48 slots in which a double layer winding is housed.  Each coil has 10 turns and is short pitched by an angle to 36° electrical.  The fundamental flux per pole is 0.025Wb.

The line-to-line induced EMF (in volts), for a two phase connection is approximately

A 4 pole, 50 Hz synchronous generator has 48 slots in which a double layer winding is housed.  Each coil has 10 turns and is short pitched by an angle to 36° electrical.  The fundamental flux per pole is 0.025Wb.

The fifth harmonic component of phase emf
(in volts), for a three phase star connection is

A 1000 kVA, 6.6 kV, 3-phase star connected cylindrical pole synchronous generator has a synchronous reactance of 20 Ω. Neglect the armature resistance and consider operation at full load and unity power factor.        

The induced emf (line-to-line) is close to

A 500 MW 3-phase Y-connected synchronous generator has a rated voltage of 21.5 kV at 0.85 pf. The line current when operating at full load rated conditions will be

It is desirable to eliminate 5th harmonic voltage from the phase voltage of an alternator. The coils should be short-pitched by an electrical angle of

A three phase alternator is wound with a 60 degree phase-spread armature windings and develops 300 kVA. If the armature is reconnected utilizing all the coils for single phase operation with a phase spread of 180 degrees, the new rating of the machine is

The armature of a single phase alternator is completely wound with T single turn coils distributed uniformly. The induced voltage in each turn is 2V (rms). The emf of the whole winding is

The distribution factor for a 36 slot stator with three-phase, 8-pole winding, having 120° phase spread, is _____________