Which of the following statements is true about Nikola Tesla's contributions?

• A. He solely invented the phonograph
• B. He was a major proponent of direct current systems
• C. His AC innovations transformed electrical power transmission
• D. He worked primarily in the field of chemical engineering

Answer: (C)

Nikola Tesla's contributions are significant primarily due to his pioneering work in alternating current (AC) systems, which revolutionized the way electrical power is transmitted and used. The adoption of AC over direct current (DC) allowed electricity to be transmitted over long distances more efficiently, facilitating the widespread use of electricity in homes, industries, and cities. Tesla's innovations, such as the development of the AC motor and the transformer, were crucial in enabling this transition.

In contrast, Tesla did not invent the phonograph; that invention is attributed to Thomas Edison. While he did have some interactions with direct current systems early in his career, he is more famously known for advocating for AC systems. Additionally, Tesla's main focus was on electrical engineering rather than chemical engineering, which diverges from his established legacy in electrical innovations. Thus, the statement regarding his contributions to AC technology is the one that accurately reflects his impact on the field.