Electrical Circuit

Electrical Circuit

Circuits are documented as schematic diagrams where standard symbols represent individual components.

• This circuit comprises 3 components, from left to right:
  • A battery,
  • A switch,
  • A light bulb acting as a "load".
  • Conductors (wires) interconnect the components.
  • The circuit could be a flashlight or some laboratory experiment.
• As depicted, it is an open circuit:
  • The switch is an "open" position, there is no continuity.
  • The circuit, present across the terminals of the battery, does not form a complete uninterrupted loop.
  • No current can flow through the circuit.

• This other representation shows a closed circuit:
  • The switch is in a "closed" position.
  • A complete and conductive loop is present across the terminals of the battery; a current runs through that path.
  • The battery, an electrical energy source, pushes a current through the circuit; that energy source feeds the load where work is performed. The light bulb shines.
• You will have noticed that the terms "open" and "closed" describe the state of the loop (path) or circuit.

Electricity always depends on a return path to the source; this is why you do not want to be part of the circuit when high voltage is involved.