Red Seal Electrician Practice
AC theoryQuestion 954 of 1506

Why are antennas and RF power conductors often made from hollow metal tubes?

  1. Hollow tubes have a lower DC resistance than solid rods
  2. Hollow tubes carry more current at 60 Hz than solid wire
  3. Hollow tubes stop the skin effect from happening
  4. RF current does not use the middle of the metal anyway
Show answer

Correct answer: RF current does not use the middle of the metal anyway

RF current stays at the surface, so a hollow tube saves weight and cost with no loss in performance.

Source: Lessons in Electric Circuits II: AC (Kuphaldt), 3.6: What Is the Skin Effect? The Skin Depth of Copper in Electrical Engineering

Practice ac theory

Questions last reviewed: 18 October 2026