What is the formula used to determine voltage when current and resistance are known?

The formula used to determine voltage when current and resistance are known is E = I x R. This equation is derived from Ohm's Law, which states that voltage (E) in a circuit is directly proportional to the current (I) flowing through it and the resistance (R) that opposes that current. This relationship allows us to calculate the voltage across a component in a circuit when we know the amount of current and the resistance value.

In practical terms, if you have a current flowing through a resistor, multiplying the current by the resistance gives you the voltage drop across that resistor. This fundamental concept is essential for analyzing electrical circuits and understanding how voltage, current, and resistance interact within them.

The other potential answers reflect misunderstandings of these relationships; they provide incorrect expressions that do not accurately represent Ohm's Law and would not yield correct results for voltage when using known values of current and resistance.