Electricity, How It WorksElectricity, how it works: When I was in high school the only thing I knew about electricity was that the teacher knew all about it. Unfortunately for me he may as well have been speaking in Russian. Since then I have worked out a fair bit of it. The best place to start is with the three things that affect the flow rate of electricity. These are voltage, current and resistance. Don't panic, these are easy to understand. I will match these three up to things we experience in our daily lives. Using water flowing through a pipe is a good place to start. VOLTAGE: This is the pressure the water is under. We can also think of this as the force that we push or pull something with. Effort is another word we can use here. CURRENT (Amperes): This is the amount of water passing through the pipe at any point in time. The wider the pipe, the greater the current. We can also liken this to the speed of an object. RESISTANCE: This can be seen as blockages in the water pipe. It can also be seen as friction which acts to slow down a moving object.
They Are All RelatedThe hardest thing to come to grips with is the related nature of these three things. Any change in one of the three changes the others. Perhaps it is this fact that makes electricity such a hard concept to grasp. The classic equation that shows this relationship is V = IR, meaning voltage (V) = current (I) x resistance (R). If you are like me that does not help in the slightest. To make this more palatable, I have prepared some pictures to show you how this can work in non-electric systems. Example 1: Pushing A CarIn this example, the force the person uses, which is the voltage, affects the speed at which the car will move (the current). If you've ever had to push a car, you will know how this works! The harder you push, the faster it goes.
Let's put that into physics-speak: as Voltage increases, Current increases. Example 2: Pushing Successively Heavier VehiclesAnother take on the above example is that of pushing a light car compared to pushing a bus. The heavier car takes a heck of a lot more effort to move than the light one. Have a look:
The weight of the cars is like resistance in electric circuits; it makes it harder to move. The more weight, the more pressure you need to make the car move. In other words, as resistance increases, you need to increase voltage to keep the same current. (more examples to be added soon) Return from Electricity How It Works to Photovoltaic Solar Cell or return to the Green Planet home page for more Solar Power Facts.
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