Back in... Light?

Back in Black is one of the most well-renowned songs from the band AC/DC. However, in physics AC/DC means something totally different; alternating current and direct current. The band even alludes to this meaning in one of their more famous logos (something I've always found hilarious).

Before I start talking currents, let me first explain about electricity. Electricity is defined as any phenomenon associated with motionless or in-motion ions. For a current to be able to move, there must be a circuit. This circuit allows for the ions to move from a positive end to an element in the circuit, providing it with power before returning to the negative end. Batteries, wires, and things such as capacitors, resistors, or lightbulbs are commonly found in circuits.

There are three main types of circuits: a series circuit, a parallel circuit, and a combination circuit. Series circuits have only one pathway that the ions can flow, and are constructed with series connections, as seen below.

Parallel circuits, on the other hand, have multiple ways that ions can flow. In other words, each element in the circuit has its own positive track and negative track to run.

Combination circuits are what their name implies. They are simply a mix of both a series circuit and a parallel circuit.

Now we can talk about currents. Direct current has the ions always flowing in one constant direction, as opposed to alternating current. Alternating current has the ions constantly switching directions.

Electricity is a topic I have never really found difficult. At the age of eight I had been immersed in circuitry, forming different types of circuits in order to complete an objective. I suppose that alternating current has been a more difficult topic for me to grasp though; seeing as I have always dealt with direct current.

Looking at problems (we haven't actually covered electricity in my class), I noticed that even though it seems to be simple, you have to really know what you're doing, such as in the case of resistors, or else it's possible to get lost easily. Also, while looking at resistor problems, it seemed that in order to solve the problems, you had to know various laws and concepts well in order to arrive at the final answer, which is something I'm still not adept at in physics.


Currents can be seen at work every day. Anything that runs on batteries is generally using direct current. This includes a flashlight, your cell phone, and a laptop. Conversely, anything that plugs into the wall for power uses alternating current, such as a clothes washer or oven lights. There are also AC/DC converters so that an appliance that uses direct current can use alternating current, and vice versa.


Just because I really like the band AC/DC, here's Back in Black, considered to be one of the greatest songs of all time.

Back in Black

Sources:

BerkeleyPoint. "How to Wire a Circuit in Parallel?" How To Wire A Circuit "In Parallel"?. Berkeley Point, 2012. Web. 25 Apr. 2012. <http://www.berkeleypoint.com/learning/parallel_circuit.html>.

ComPadre. "Electric Current." What Is An Electric Circuit?. The Physics Classroom, 2012. Web. 25 Apr. 2012. <http://www.physicsclassroom.com/class/circuits/u9l2a.cfm>.

Dictionary.com. "Electricity." Electricity|Define Electricity At Dictionary.com. Dictionary.com, 2012. Web. 25 Apr. 2012. <http://dictionary.reference.com/browse/electricity?s=t>.