What is increased in a generator when coils are connected in series?

When coils in a generator are connected in series, the voltage output of the generator increases. This occurs because connecting coils in series combines their individual voltages, resulting in a higher total voltage. Each coil generates its own electromagnetic potential, and by connecting them in series, the total voltage is the sum of the voltages of each coil.

In a series configuration, while the overall current flowing through the coils may remain constant, the voltage output can significantly increase, making the generator more capable of supplying higher voltages for various applications. This principle is central to the design of generators and electrical circuits and highlights how series connections leverage the additive property of voltage in electrical systems.