What type of electrical testing would you use to verify the operation of a transformer?

The most appropriate choice for verifying the operation of a transformer is "Transformer Testing." This specific type of testing is designed to evaluate the performance and functionality of transformers, ensuring they are operating within their intended specifications. Transformer testing encompasses various methods, such as insulation resistance tests, turns ratio tests, and power factor tests, which all contribute to diagnosing the condition and reliability of the transformer.

Load testing, while relevant for evaluating how equipment performs under real operating conditions, is broader and typically applies to a variety of electrical equipment beyond just transformers. Circuit testing usually pertains to checking the continuity and functionality of circuits rather than the specific operation of a transformer itself. Ground testing focuses on ensuring that grounding systems are effective and safe but does not address the operational characteristics of a transformer.

Thus, transformer testing is the most specialized approach for confirming that a transformer operates correctly and safely in its designated application.