Page 267 - Solutions Manual to accompany Electric Machinery Fundamentals

The resulting terminal characteristic is shown below. Note that the armature reaction reduces the terminal
voltage for any given load current relative to a generator without armature reaction.

8-26. If the machine in Problem 8-25 is running at 1800 r/min with a field resistance R adj = 10  and an

armature current of 25 A, what will the resulting terminal voltage be? If the field resistor decreases to 5 
while the armature current remains 25 A, what will the new terminal voltage be? (Assume no armature
reaction.)
SOLUTION If I A = 25 A, then IR  A A 25 A 0.18   = 4.5 V. The point where the distance between the

E A and V T curves is exactly 4.5 V corresponds to a terminal voltage of 114 V, as shown below.

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