25. The machine in Problem 8-22 is reconnected as a shunt generator and is shown in Figure...

25. The machine in Problem 8-22 is reconnected as a shunt generator and is shown in Figure P8-9. The shunt field resistor Radj is adjusted to 10 and the generator's speed is 1800 r/min.

(a) What is the no-load terminal voltage of the generator?

(b) Assuming no armature reaction, what is the terminal voltage of the generator with an armature current of 20 A? 40 A?

(c) Assuming an armature reaction equal to 300 ?-turns at full load, what is the terminal voltage of the generator with an armature current of 20 A? 40 A?

(d) Calculate and plot the terminal characteristics of this generator with and without armature reaction.