Which term describes a switch that is operated by a physical key?

• A. Pilot switch
• B. Key switch
• C. Toggle switch
• D. Pushbutton switch

Answer: (B)

A switch operated by a physical key is a key switch. It provides security by requiring a key to turn or select the switch position, so only authorized personnel can energize or control the equipment. The key is inserted into a cylinder and rotated to change the connection, often with the key removable in a specific position to lock the control in that state. This differentiates it from a pilot switch (which may include an indicator but isn’t typically key-operated), a toggle switch (a lever you flip), or a pushbutton switch (activated by pressing a button). In practice, the key switch is used to restrict access to starting or stopping machinery, adding a simple form of access control to the control circuit.