Updated: Dec 9, 2025 | Source: 2022-2026 Question Pool | Topic: T6A
T6A01T6A

What electrical component opposes the flow of current in a DC circuit?

Deep Dive: T6A01

The correct answer is B: Resistor. A resistor is the electrical component that opposes the flow of current in a DC circuit. Resistance is the property that limits current flow, and resistors are components designed to provide specific resistance values. Resistors are fundamental components in electronics. They oppose current flow by converting electrical energy into heat. The amount of opposition is measured in ohms (Ω). Resistors are used to limit current, divide voltage, provide bias voltages, and many other functions. In DC circuits, resistors provide constant opposition to current flow, following Ohm's Law (E = I × R). Understanding resistors is essential for all electronics work.

Why Other Answers Are Wrong

Option A: Incorrect. Inductors oppose changes in current (AC reactance), not steady DC current flow. Inductors have very low resistance to DC current. Option C: Incorrect. An inverter converts DC to AC, it doesn't oppose current flow in a DC circuit. It's a power conversion device. Option D: Incorrect. Transformers transfer AC energy between circuits, they don't oppose DC current flow. Transformers don't work with DC.

Exam Tip

Resistor opposes DC current. Remember: Resistors are components that oppose the flow of current in DC circuits by providing resistance, measured in ohms.

Memory Aid

**R**esistor = **R**esists **C**urrent (think 'R = RC')

Real-World Example

You're building a simple LED circuit. You need to limit the current to protect the LED. You add a resistor - it opposes the current flow, limiting it to a safe value. The resistor converts excess electrical energy into heat, protecting your LED while allowing proper operation.

Source & Coverage

Question Pool: 2022-2026 Question Pool

Subelement: T6A

Reference: 2022-2026 Question Pool · T6 - Electrical components

Key Concepts

Resistor Resistance Current opposition DC circuit

Verified Content

Question from the official FCC Technician Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the T6A topic.