Ohm's law is a principle in electric circuits that describes the relationship between voltage, current, and resistance.

If you know two of the three values of voltage, current, or resistance, you can calculate the third.
There are three types of formulas as follows.

Voltage (V) = Resistance (R) × Current (I)
Resistance (R) = Voltage (V) ÷ Current (I)
Current (I) = Voltage (V) ÷ Resistance (R)

Use the diagram below and let's learn the formulas!

For example, if you want to find the voltage, hide the "voltage" at the top.
Then you can see that the formula is "resistance" × "current".