Ohm's Law: The Complete Guide to Understanding Voltage, Current, and Resistance Ohm's Law is the single most important relationship in basic electronics and electrical engineering. It describes how voltage, current, and resistance interact in a circuit, and it forms the foundation for nearly every calculation an electrician, hobbyist, or engineering student will ever perform. Whether you're sizing a resistor for an LED circuit, troubleshooting a faulty appliance, or...