What is the voltage across a 2-ohm resistor if a current of 0.5 amperes flows through it?

To find the voltage across a resistor when you know the current and the resistance, you must use Ohm's Law. The formula for Ohm's Law is E = I x R, where E stands for electromotive force (voltage), I stands for current, and R stands for resistance. In this specific problem, plug the given values into the formula: E = 0.5 amperes x 2 ohms. Multiplying these together gives a result of 1 volt. The incorrect options result from using the wrong mathematical operation. For example, dividing the current by the resistance (0.5 / 2) would incorrectly give 0.25 volts, which is a common misapplication of the formula.