Question T5A11
From subelement T5 - T5A
What type of current flow is opposed by resistance?
Why is this correct?
Resistance opposes ALL types of current flow — direct current (DC), alternating current (AC), and radio frequency (RF) current. Whether electrons flow in one direction (DC), alternate directions (AC), or at high frequencies (RF), resistance creates opposition to that flow. The physical property of resistance doesn't discriminate based on current type; it impedes electron movement regardless of the current's characteristics.
Memory tip
Remember this pattern: resistance is a fundamental electrical property that acts universally. When a question asks about resistance opposing current and lists different current types, look for 'all' answers — resistance doesn't pick favorites among current types.
Learn more
In practical amateur radio operation, you'll encounter resistance in antenna systems, transmission lines, and RF circuits. Whether you're dealing with DC bias voltages in amplifiers, AC power supply circuits, or high-frequency RF signals propagating through coaxial cable, resistance creates power losses and voltage drops. Understanding that resistance affects all current types helps you troubleshoot everything from battery drain issues to SWR problems in your station.
Think about it
Why do you think resistance behaves the same way regardless of whether current flows steadily in one direction or rapidly alternates back and forth millions of times per second?