Nikola Tesla is famous for several key inventions in the development of electrical engineering, including the alternating current (AC) system. Tesla's innovations made significant advancements in electrical distribution and efficiency, ultimately shaping the modern electricity supply system. He developed the Tesla coil and contributed to the invention of the radio and induction motor as well. Tesla's visionary ideas and patented technologies laid a foundation for future advancements in power generation and electrical systems that are still relevant today.