Name the three basic components of a circuit.

• A. Switch, Conductor, and Load
• B. Source, Resistor, and Ground
• C. Transformer, Conductor, and Sensor
• D. Source, Conductor, and Load

Answer: (D)

In the simplest view, a circuit needs three basic elements: a source of electrical energy, a conductor to provide a path for current, and a load that uses the energy. The source supplies the voltage and pushes current through the circuit. The conductor forms the route that allows that current to flow from the source to the load. The load is the component or device that consumes the energy—like a lamp, motor, or resistor—and converts electrical energy into light, motion, or heat.

A switch isn’t part of the essential trio; it’s a control that can connect or disconnect the circuit. Ground isn’t always present in every circuit and isn’t one of the universal three components. Other options introduce elements that aren’t required for the basic understanding of a simple circuit.