What is an open circuit?

An open circuit is characterized by a pathway that does not allow electricity to pass through. This occurs when there is a break in the circuit, meaning that the electrical pathway is incomplete. As a result, the flow of electric current is interrupted, preventing any devices connected to the circuit from functioning.

In contrast, a closed circuit provides a complete path for the electric current, allowing it to flow continuously. High resistance does not define an open circuit; it merely implies that the current may face difficulty moving through the circuit but does not inherently disrupt the pathway. As for electric equipment, an open circuit is not a type of equipment but rather a condition of the circuit itself. Thus, the defining feature of an open circuit is indeed that it does not allow electricity to flow, which aligns with the correct answer.