What type of chemical process is mentioned in Article 668?

The reference to Article 668 specifically deals with electrolytic cells, which are systems that conduct electricity through a liquid or solution to drive a chemical reaction. Electrolytic processes involve the use of electric current to facilitate chemical changes, such as electrolysis, where compounds are broken down into their elemental components.

This choice is pertinent because electrolytic cells are essential in various applications including metal plating, galvanization, and the production of chemicals. The application of electricity in these processes highlights the critical interplay between electrical engineering and chemical reactions, which is vital knowledge for someone preparing for a supervising electrician's role, especially in a city like Chicago where adherence to specific codes and regulations is critical.

The other options refer to different fields or processes that do not align with the focus of Article 668. Induction heating, while electrical in nature, pertains more to heating through electromagnetic induction rather than a chemical change. Industrial machinery and X-ray equipment relate more to physical machinery and imaging techniques respectively, rather than the chemical processes discussed in Article 668. This clarity reinforces the importance of understanding the specific technical context of the question.