Ohm's Law is one of the fundamental principles in electrical engineering. It describes the relationship between three key electrical quantities: voltage, current, and resistance. This law helps us understand how electricity flows through circuits and forms the foundation for analyzing electrical systems.
The mathematical expression of Ohm's Law is V equals I times R. Here, V represents voltage measured in volts, I represents current measured in amperes, and R represents resistance measured in ohms. This formula shows that voltage is directly proportional to both current and resistance. Let's see how changing these values affects the circuit.
Ohm's Law can be rearranged into three different forms. We can solve for current by dividing voltage by resistance, or solve for resistance by dividing voltage by current. This graph shows how current changes inversely with resistance when voltage remains constant. As resistance increases, current decreases following a hyperbolic curve.
Let's solve a practical example. We have a 12-volt battery connected to a 4-ohm resistor, and we need to find the current. Using Ohm's Law, current equals voltage divided by resistance. So I equals 12 volts divided by 4 ohms, which gives us 3 amperes. The current flows in a complete loop through the circuit.
Ohm's Law has numerous practical applications in electrical engineering. It's essential for circuit design, power calculations, component selection, and troubleshooting. The key relationship V equals I times R shows that voltage is proportional to current at constant resistance, and current is inversely proportional to resistance at constant voltage. This fundamental law forms the foundation for understanding electrical circuits and is used daily by engineers and technicians worldwide.