Automotive Electronics Practice Test

In an electrical circuit, which component directly opposes current flow?

1. Capacitor

2. Inductor

3. Resistor

4. Battery

The correct answer is: Resistor

The component that directly opposes current flow in an electrical circuit is the resistor. Resistors are designed to provide resistance, which is a measure of how much they impede the flow of electric current. When current passes through a resistor, it encounters opposition, leading to a drop in voltage across the resistor according to Ohm's Law (V = IR, where V is the voltage, I is the current, and R is the resistance). This property is crucial in many applications, such as controlling the amount of current that flows through different components, setting bias points in transistors, and protecting sensitive components from excessive current. While capacitors and inductors have their own roles in influencing current through reactance (capacitance and inductance), they do not primarily function to oppose current flow in the same direct manner as resistors do. A battery, on the other hand, provides the electromotive force (voltage), which pushes current through the circuit but does not oppose it.