Series vs. Parallel Circuits - Questions 15 Help

Wiring two or more devices together in a circuit can be done in a variety of ways. The two most common ways are to wire the devices in a series circuit or as a parallel circuit. Whether the devices are in a series or a parallel arrangement affects the properties that the circuit would exhibit.

Series Circuits are characterized by a single pathway from the + to the - terminal of the battery. The bulbs are arranged in a consecutive fashion such that any charge that passes through the first bulb will also pass through the second and the third bulb. As a charge passes through a bulb there will be a loss of electric pressure. We sometimes call it a voltage drop. Since charge passes through all three bulbs of a series circuit, there is a combined voltage drop resulting from each stepwise loss of voltage in each bulb. This combined drop in voltage is equivalent to the voltage of the battery. In effect, this total voltage drop is divided (unevenly between the bulbs in the series circuit. Adding a fourth bulb will thus decrease the voltage drop for all pre-existing bulbs since now the total battery voltage will have to be shared four-ways instead of three-ways.

Parallel circuits are quite different because the bulbs are all placed in an individual branch with each branch operating independent of the others. A charge making a loop around the circuit will only pass through a single bulb. The passage through that bulb results in a voltage drop that is equal to the voltage of the battery. And so regardless of which bulb a charge passes through, the voltage drop will always be the same amount - an amount equal to the battery's voltage. Adding another bulb to a fourth branch will not affect any of the pre-existing voltage drops since all voltage drops are always equal to the battery's voltage.