 Let's take a look at some example problems for Ohm's law. Now Ohm's law gets written out in several different formats, but it's defined by the fact that a material which follows Ohm's law, if you divide the voltage by the current, you'll get a constant value for the resistance. So even as you increase the voltage, the resistance would increase proportional to that, giving you a constant resistance. So that sort of defines the materials for which Ohm's law works. We can then rearrange that equation into a form that solves for the voltage. And this is the one I'm used to seeing as being Ohm's law. Or you can rearrange the equation a little bit more and solve that for the current itself. Now in my classes, we use a delta V for the voltage. In some classes, you'll see just a V for the voltage. So be aware of that. If we take our equation for Ohm's law here in terms of the voltage and we plug in values for the current and the resistance, then you'll get the value for the voltage. In this case, I've put in 1.25 amps, 4.00 Ohms. And remember, this capital omega stands for Ohms. That gives us our 5 volts. So a volt must be equal to an amp times an Ohm. And I cover that in my introduction to Ohm's law video. As with most of my example problems, I want to remind you to be careful about metric prefixes. For example, you might have the current expressed in milliamps. And the resistance might be in kiloohms, in which case you're going to want to actually put in the scientific notation for each of those metric prefixes. In this case, because one's 10 to the minus 3 and the other's 10 to the positive 3, they actually balanced each other out and you still had 5 volts. But if these were different metric prefixes, you might have to be a little bit more careful about that. We can use the rearranged formulas. And I'm just going to use the same numbers so you can see how everything relates to each other. That if you're given the voltage and the current, you can use that to solve for the resistance. Or if you're given the voltage and the resistance, you can use that to solve for the current. And you'll see different equations popping up. So for example, if you know the resistance and the voltage in a particular circuit, this allows you to find the current. But in some other circuit where maybe you've got a combination of things, you might know the current flowing through it and the resistance. And that would let you know the voltage. In these equations, we're typically looking at the absolute value. So current has a direction and so does voltage. If you go through the resistor in one direction, the voltage drops. If you go through the resistor in the other direction, the voltage increases. And we haven't taken that into account in this equation. We've just found out how much the potential changes, which is what our voltage is. So these are just a few examples of some calculations using Ohm's law.