Definition

1. Noun:
   • A complete electrical circuit around which current flows or a signal circulates: A closed circuit is a continuous, unbroken path that allows electricity or an electronic signal to travel from a power source, through components, and back to the source. It is the fundamental requirement for electrical devices to operate.

Usage

• The term "closed circuit" is primarily used in technical contexts related to electricity, electronics, and security systems.
• It describes a functional, active electrical loop. Its opposite is an "open circuit," where the path is broken and current cannot flow.
• In security, "closed-circuit television (CCTV)" uses this principle, where the video signal is transmitted over a private, dedicated network (a "closed" system) rather than being broadcast publicly.

Examples

• Noun:
  • For the light bulb to illuminate, you must have a closed circuit connecting it to the battery.
  • The engineer tested the device to ensure it formed a proper closed circuit.
  • The building's security is monitored by a closed-circuit television system.

Advanced Usage

• "To close a circuit": This verb phrase describes the act of completing an electrical path, allowing current to flow.
  • Close the circuit by flipping the switch to the 'on' position.
• Conceptual Use: The idea can be applied metaphorically to describe any complete, self-contained system or loop of information.
  • The feedback from the survey created a closed circuit of information between the company and its customers.

Variants and Related Words

• Closed-circuit television (CCTV) (n): A television system in which signals are transmitted over a private network to a specific set of monitors.
  • The store installed closed-circuit television to deter theft.
• Circuit (n): The complete path that an electric current can flow around.
• Open circuit (n): An electrical circuit that is not complete, so current cannot flow.

Synonyms

• Complete circuit: A circuit with a continuous path for current.
• Loop: A structure, series, or process that ends where it begins.

Antonyms

• Open circuit: A broken or incomplete electrical path that prevents current flow.

Related Phrases

• (To be) live: In electrical terms, a circuit is "live" when it is closed and conducting current.
  • Be careful, that wire is part of a closed circuit and is live.

Noun

1. a complete electrical circuit around which current flows or a signal circulates