Ohm’s Law

Use the following illustration to discover Ohm’s Law that describes the relationship between voltages, resistance, and current.

Click the image below to view the animation.

For our purposes, we will assume the resistances spoken of abide by Ohm’s Law. Use the linear relationship in all your calculations that include resistance unless otherwise specified.

At this point, it is important to note that a battery does not provide current; it induces current by providing a constant potential difference (voltage) between its terminals. Current passes through a wire and depends on the resistance in that wire. Current is not "used up" as the battery goes "dead"—the amount of charge going into one end is the same amount of charge coming out. When a battery can no longer transform chemical energy into electrical energy, it can no longer provide a potential difference to induce a flow of charge. This is when the battery becomes useless for an electrical circuit.