What is an open circuit?

• A. A circuit with a closed loop and no resistance.
• B. A circuit with an incomplete path, preventing current flow.
• C. A circuit where current is flowing freely.
• D. A circuit connected to a power source but with no load.

Answer: (B)

An open circuit means the path for electricity is not complete. There is a break or gap in the conductor so current cannot flow back to the power source. You can still have a voltage present across the gap, but the circuit isn’t closed, so no current moves.

That’s why describing it as an incomplete path that prevents current flow is the best fit. In a closed circuit the loop is complete and current can flow, and in a circuit with no load there may be no device using power but the path can still be complete.