Explain why the output voltage of an over-compound generator increases as the load increases?

In an over-compound generator, the output voltage increases with load due to the design of the winding connections and the way they interact with the magnetic fields. As the load increases, the generator experiences a voltage drop due to increased armature current, but the series field winding generates additional magnetic flux. This enhanced flux counteracts the voltage drop, leading to a rise in output voltage to maintain the desired level, thereby compensating for the load variations.