Final answer:
Voltage sources like batteries can be connected in series, parallel, or a combination, affecting total emf and current capacity. Parallel connections are used to maintain voltage and increase current capacity, while combinations of series and parallel allow for complex circuit behaviors.
Step-by-step explanation:
Voltage sources, such as batteries, can be connected in various configurations just like resistors, which include series, parallel, or a combination of both. When batteries are connected in parallel, they maintain the same voltage but provide a greater total current capacity due to a reduced total internal resistance. Another typical example is components in a vehicle or a household that are connected in parallel to the voltage source to allow them to operate independently and with a full voltage supply.
In more complex electrical systems, we often see a combination of series and parallel connections. For instance, wire resistance is commonly in series with other resistances that might be in parallel within a circuit. This affects the overall equivalent resistance and the behavior of the circuit. Mechanical representations such as electroplaques in electric eels show a similar arrangement that allows the eel to produce a substantial emf through its biological cells.