Which of the following is not an advantage of an inverter power source?

• A. Smaller transformer
• B. Lightweight and portable
• C. Higher efficiency
• D. Larger transformer

Answer: (D)

Inverter power sources achieve portability and efficiency by using high-frequency switching, which lets them use a much smaller transformer. That smaller transformer is a key reason these welders can be light, compact, and easy to move. The solid‑state switching also helps improve efficiency by reducing heat and allowing precise control of the output, so you get more welding performance with less energy waste. A larger transformer, on the other hand, would add bulk and weight and would waste more energy, so it’s not an advantage of inverter systems.