Parallel Circuits

Parallel Circuits differ from series circuits because unlike series, parallel circuits have a choice. They are not restricted to only one path. There are several paths for the current to pass through in a parallel circuit. Although more of the current will choose the path with the least resistance the current will also travel though the alternate path(s).

• This is an example of a parallel circuit in which there are three resistors connected to a battery. The seperate paths available to the current are clearly differenciated through seperate segments of the circuit in which a choice is available.

In parallel circuits, voltage remains constant in every resistor. V Total = V1 = V2 ……

The current is different in every resistor and therefore the total current is the sum of the currents in each resistor. Therefore, I total = I 1 + I 2 + I3…..

The interesting thing about finding the total resistance in a circuit, is that you must first find the value of 1/total resistance. 1/R total = 1/R1 + 1/R2 + 1/R3 …

Parallel circuits also differ from series circuits because for example in a parallel circuit with three light bulbs (resisters) when one light goes out the other two stay on where as in a series circuit if one light bulb goes out the other two will also go out.