Warning lights are set up to alert personnel to danger or to alert the operator to a change in machine status.

• A. Set up to alert personnel to danger or to a change in machine status
• B. Always indicate faults
• C. Only used for machine status
• D. Only for external devices

Answer: (A)

Warning lights are visual signals that communicate important information about a machine to people nearby. Their main purpose is to alert personnel to danger or to a change in machine status so they can respond appropriately, such as stopping the machine or checking a process. They’re not limited to indicating faults; they can signal various changes in condition that require attention. They aren’t restricted to only the machine’s internal state or only to external devices—the key idea is that they quickly alert people to risk or a status change.