What is the current through a 100-ohm resistor connected across 200 volts?

Ohm's Law states that the current flowing through a circuit is directly proportional to the voltage and inversely proportional to the resistance. The standard formula to find current is I = E / R, where I is current, E is voltage, and R is resistance. Using the values given, you set up the equation as I = 200 volts / 100 ohms. This simple division clearly results in 2 amperes. Choosing 0.5 amperes means you incorrectly divided the resistance by the voltage (100 / 200). Choosing 20,000 amperes means you multiplied the values together instead of dividing.