What is a Circuit? Understanding Electrical Paths, Voltage, and Current

The basics of electricity are voltage, current, resistance, and power.

• Power is the rate at which electrical energy is converted or transferred and is typically measured in watts.
• Voltage is the pressure from the power source and is measured in volts.
• Current is the rate of electrical energy passing through a point in the circuit, usually measured in amps.
• Resistance is the opposition to the flow of electric current in a circuit, expressed in ohms. Ohm’s law is a basic law of electricity that describes how voltage, current, and resistance relate to each other.

Electricity follows the path of least resistance. An electrical circuit is a roadmap for electricity to perform a specific task. It is a closed loop where electrical current can flow from the power source to the load or device and then return to the power source. A circuit consists of a power source, conductive paths (wires), and a device or load that uses the power, such as a light bulb.

Think of it like your daily commute, where your house is the power source (like a battery), the roads to work are the path the electricity takes to power a device, and the drive home completes the circuit.

Parallel Circuits: Taking Multiple Paths

A parallel circuit consists of multiple paths for electricity to flow. Each component is connected directly to the power source, and the electricity splits into multiple paths to power the different components before merging back together. The voltage remains the same across each path of the parallel circuit. If one path is broken, the current can still flow through the other paths, so the other components continue to operate.

Series Circuits: A Sequential Path

In a series circuit, all components or devices (such as light bulbs) are connected in a single loop, and the electricity must pass through each device in sequence. An equal amount of current flows to every device in the circuit, and if one connection is broken, the entire circuit stops working, and no current flows.

Switches: Opening and Closing the Path

A switch acts as the gatekeeper in a circuit, controlling the flow of electricity by either closing the path or opening the path for current to flow. It responds to an external force to mechanically change an electric signal.

• If the switch is on, the path is open, and electricity flows.
• If the switch is off, the path is closed, and no current can pass.

Dimmers: Slowing the Flow

In a circuit, a dimmer switch reduces the amount of electricity flowing, affecting the power to a device, impacting the brightness of a light.

Wires in Circuits

Wires in a circuit provide a path for the electricity to flow from the power source to the load or device. The size of the wires in a circuit determines how much electricity can flow. Ideally, wires will provide minimal resistance to the flow of electricity to provide enough power to the device/load. A longer, thinner wire increases resistance and reduces the flow of electricity, while a thicker, shorter wire can carry electricity more efficiently.

The Circuit Roadmap

A circuit diagram is like a roadmap of all these electrical paths, showing where the electricity flows and how different components are connected. Understanding this roadmap helps in designing circuits that efficiently power devices while preventing bottlenecks, roadblocks, or overloads. By thinking of a circuit as roadways or paths, it becomes much easier to visualize how electricity moves and interacts with different components in a system.