A DC Circuit, otherwise known as a Direct Current Circuit, can be either in series or parallel, or in super FUN combinations, COMPLEX!!! It is driven by a Direct Current. All of the electrons in this current flow through the circuit in one constant direction. The path of these electrons is changed depending on the type of circuit, series or parallel. There is also voltage from the batteries, and using this voltage combined with the resistors you can find the current. The current also requires a conductor, which is the wire, and a resistor, the light bulb.

**Series**

In a series circuit, all of the electrons flow through the resistors. As you can see in the diagram, the electrons are all in one path and do not split onto any other paths. The current through the series circuit is the same at all points along the wire. There is the voltage provided by the batteries, and, if the light bulbs resistances were not equal, then the voltage across each would vary. But since the resistors are the same, the voltage is the same. And as the resistance increases when more bulbs are added, the current decreases. More importantly, since the current runs through the resistors, if one resistor is removed the whole circuit goes out.

**Parallel Circuit**

In a parallel circuit, each resistor provides a new path for the electrons to flow through. In the diagram, the electrons meet at the parallel circuit, and then split into two paths. The voltage across each resistor in a parallel circuit is equal to the voltage total. Again, in this case, the resistors are equal so the current through each resistor does not vary, but the total current is the sum of the currents through each resistor. If the resistance did vary in each light bulb, then you would just use the same process to find each current and add them to find the total current. When there is more resistance, the current decreases because the resistance total still increases. But, a very important difference from series in this circuit is that even though one bulb is removed, the circuit still works.

**Complex Circuit**

In a complex circuit, it is a combination of series and parallel circuits. The first bulb is in series so it’s current is equal to the total current. The current through the parallel circuit is the same as the total as well, but it is split into both legs. This is demonstrated by the magnitude of the light beams. The voltage in the series resistor is found using the current and the resistance. After finding the voltage across the series resistor , you can just subtract that from the total voltage to find the voltage across the parallel resistors. The total resistance is found by splitting each leg up: you find the total resistance in the parallel portion, then add it to the total resistance of the series light bulb. If the resistance varies in the parallel portion, then the voltage will vary across each, but still in total it will be equal to the left over voltage. If I were to take out the top lightbulb in the parallel circuit, the circuit would still continue but the bottom bulb would be much lighter, and vise versa with the other bulb. But, if I were to take out the bulb in series, the whole circuit would turn off because it breaks the circuit. So, even though it is a ‘complex’ circuit, if broken up it’s pretty easy to just take the two previous concepts and combine them.

**Well**, that's it for the blog guys. It's been a great year in physics and I will miss this class. Thanks Mrs. Gende for all of the fun projects and fun concepts, you helped me learn alot!

So long blog...