An electrical circuit is a device that uses electricity to perform a task, such as run a vacuum or power a lamp. The circuit is a closed loop formed by a power source, wires, a fuse, a load, and a switch. Electricity flows through the circuit and is delivered to the object it is powering, such as the vacuum motor or lightbulb, after which the electricity is sent back to the original source; this return of electricity enables the circuit to keep the electricity current flowing. Three types of electrical circuits exist: the series circuit, the parallel circuit, and the seriesparallel circuit; depending on the circuit type, it may be possible for electricity to continue flowing should a circuit stop working. Two concepts, Ohm's Law and source voltage, can affect the amount of electricity flowing through a circuit, and therefore, how well an electrical circuit functions.
Most devices that run on electricity contain an electrical circuit; when connected to a source of power, such as being plugged into an electrical outlet, electricity can run through the electrical circuit within the device and then return to the original power source, to continue the flow of electricity. In other words, when a power switch is turned on, the electrical circuit is complete and current flows from the positive terminal of the power source, through the wire to the load, and finally to the negative terminal. Any device that consumes the energy flowing through a circuit and converts that energy into work is called a load. A light bulb is one example of a load; it consumes the electricity from a circuit and converts it into work — heat and light.
A series circuit is the simplest because it has only one possible path that the electrical current may flow; if the electrical circuit is broken, none of the load devices will work. The difference with parallel circuits is that they contain more than one path for electricity to flow, so if one of the paths is broken, the other paths will continue to work. A seriesparallel circuit, however, is a combination of the first two: it attaches some of the loads to a series circuit and others to parallel circuits. If the series circuit breaks, none of the loads will function, but if one of the parallel circuits breaks, that parallel circuit and the series circuit will stop working, while the other parallel circuits will continue to work.
Many "laws" apply to electrical circuits, but Ohm's Law is probably the most well known. Ohm's Law states that an electrical circuit's current is directly proportional to its voltage, and inversely proportional to its resistance. So, if voltage increases, for example, the current will also increase, and if resistance increases, current decreases; both situations directly influence the efficiency of electrical circuits. To understand Ohm's Law, it's important to understand the concepts of current, voltage, and resistance: current is the flow of an electric charge, voltage is the force that drives the current in one direction, and resistance is the opposition of an object to having current pass through it. The formula for Ohm's Law is E = I x R, where E = voltage in volts, I = current in amperes, and R = resistance in ohms; this formula can be used to analyze the voltage, current, and resistance of electricity circuits.
Another important concept in regards to electrical circuits, source voltage refers to the amount of voltage that is produced by the power source and applied to the circuit. In other words, source voltage depends on how much electricity a circuit will receive. Source voltage is affected by the amount of resistance within the electrical circuit; it can also affect the amount of current, as the current is typically affected by both voltage and resistance. Resistance is not affected by voltage or current, however, but can reduce the amounts of both voltage and current to a electrical circuits.
anon259178 Post 58 
So what's the voltage drop, or current drop, across a series or parallel circuit? This article has the usual textbook stuff fluff but not the stuff I want to know. 


anon145091 Post 45 
thanks. it was very helpful. 
anon142622 Post 42 
Wow, very helpful. Thanks. Because I needed to know about all this stuff for my science exams. Thank you. Now I think I'm going to pass. Thank you. 
anon113335 Post 35 
I found it very interesting, helpful and easy to understand. 
anon105543 Post 33 
this are really helpful. thanks. 
anon93485 Post 32 
this article is so great. I've been in a computer shop about a couple of hours searching for it! this article is so helpful, but there's another thing it missed: what is the role of source, paths/line and controls in an electrical circuit? 
anon89792 Post 31 
It's good. i like it and it was very helpful. Thank you very much. 
anon89671 Post 30 
I found it is very helpful. 
anon84151 Post 28 
Wow. I've been looking for something like this for so long, and i finally find it straight and easy over here. Really helpful. Thanks bud! 


anon83776 Post 27 
good stuff there mate. 
anon80745 Post 23 
this really helped me. 
anon79374 Post 22 
this page was really helpful as i had to answer questions on electricity on my science homework and it helped me a lot! 
laser Post 21 
Very helpful. 
anon78555 Post 20 
This is really helpful 
anon75804 Post 16 
I like this page. 
anon75136 Post 15 
This was extremely helpful. Thank you. 
anon69244 Post 14 
i easily understand my report. now i know what in going to do. 
anon67424 Post 12 
It's good. i like it. 


anon49620 Post 8 
yes this was easy to understand and it gave me a lot of information to put in my essay about electricity. thank you. 
anon47241 Post 7 
it was very helpful. 
anon17842 Post 1 
I found it very helpful and easy to understand. 