Final answer:
The electrode holder should always be securely placed in its holder or clamp when turning on the welder to reduce the risk of accidental contact and injuries.
Step-by-step explanation:
When turning on the welder, the electrode holder should always be placed securely in its holder or clamp, often located on the side or top of the welder. This ensures that the electrode is not in contact with any surface, reducing the risk of accidental contact and potential injuries. Additionally, keeping the electrode holder in its designated place helps maintain a safe and organized workspace.