Which statement best describes impedance matching in AC signal transmission?

Which statement best describes impedance matching in AC signal transmission?

• A. Match source and load to maximize power transfer and minimize reflections
• B. Minimize current draw from the source
• C. Use simple resistance matching only
• D. Increase capacitor charging efficiency

Answer: (C)

Impedance matching in AC transmission is about presenting the same impedance to the source as the load presents to the line at the operating frequency, so power transfer is maximized and reflections along the line are minimized. In AC systems the impedance is complex, including both resistance and reactance from inductors and capacitors, and this reactance changes with frequency. When the source, load, and the transmission line are properly matched, the reflections are minimized, which prevents wasted power and standing waves. The description that emphasizes matching source and load to maximize power transfer and minimize reflections best captures this idea, because it directly ties together the goals of efficient transfer and reduced reflections on the line. Other choices miss key aspects: simply aiming to minimize current draw isn’t the core aim of impedance matching, and limiting to simple resistance matching ignores reactive components that matter at AC frequencies. Increasing capacitor charging efficiency isn’t about impedance matching on a transmission path.

Impedance matching in AC transmission is about presenting the same impedance to the source as the load presents to the line at the operating frequency, so power transfer is maximized and reflections along the line are minimized. In AC systems the impedance is complex, including both resistance and reactance from inductors and capacitors, and this reactance changes with frequency. When the source, load, and the transmission line are properly matched, the reflections are minimized, which prevents wasted power and standing waves.

The description that emphasizes matching source and load to maximize power transfer and minimize reflections best captures this idea, because it directly ties together the goals of efficient transfer and reduced reflections on the line. Other choices miss key aspects: simply aiming to minimize current draw isn’t the core aim of impedance matching, and limiting to simple resistance matching ignores reactive components that matter at AC frequencies. Increasing capacitor charging efficiency isn’t about impedance matching on a transmission path.