(Section 5.10)
In a circuit, we can imagine the greater the resistance (or impedance) to flow the lower the current (or flow). We can also imagine the greater the push (or voltage), the greater the current (or flow). Ohm’s Law can summarize this:
where I is the current ( in amperes ), V is the voltage ( in volts) and R is the resistance. Resistance is measured in ohms and is this unit is given the Greek letter omega.
Feel free to examine animation 5.2: Ohm’s Law if you like.
Sample Problem
In our problem we can draw a circuit diagram with the following symbols.
If we have a circuit with a 4 Ohm resistor and a 12 volt battery, what is the current?
Solution:
so
