A knife switch is a type of switch used in electrical circuits to make or break the flow of current. It consists of a pivoting metal lever, or “blade,” that is connected to one or more electrical contacts. When the blade is in the “closed” position, the contacts are connected and current can flow through the circuit.

When the blade is in the “open” position, the contacts are separated and the current is interrupted. Knife switches are commonly used in educational settings for demonstrating electrical circuits and the principles of electrical safety. They are also used in industrial settings as a means of isolating electrical equipment for maintenance or repair.