The three formulas associated with Ohm’s law are the equations that demonstrate the relationships between voltage, current and resistance and follow from the formula for determining voltage by multiplying current by resistance. Knowing any two of these variables enables the calculation of the third unknown variable.
According to Ohm’s law, V = I x R, or voltage equals current multiplied by resistance, where V is voltage measured in volts, I is current measured in amperes, and R is resistance measured in ohms. From this equation, it necessarily follows that I = V/R and R = V/I. Therefore, knowing any two of these measurements for a circuit enables the determination of the remaining characteristic.
It is worth noting that this is a somewhat simplified model of the actual operation of Ohm’s law. In practice, voltage is a measurement of the difference in electrical potential between two points on a circuit and is expressed by preceding the symbol V with the Greek letter delta, which indicates change or difference in scientific usage.