Which component in an automotive circuit is most clearly a resistive load when powered?

Prepare for the Automotive Service Technician Period 1 exam. Study with flashcards and multiple choice questions, each question has hints and explanations. Get ready for your exam!

Multiple Choice

Which component in an automotive circuit is most clearly a resistive load when powered?

A resistive load converts electrical energy to heat (and light in a bulb) with current that follows Ohm’s law: the current is proportional to the applied voltage and there’s little to no energy stored in the form of a magnetic or electric field. A standard automotive light bulb fits this behavior well—its filament simply resists the flow of current, heating up to emit light, with its resistance remaining relatively constant during normal operation. In contrast, the starter motor, the relay coil, and fuel injectors rely on magnetic fields created by coils. These are inductive loads, which store energy in the magnetic field and cause current to lag behind voltage and to change as the device operates (start-up surge, back-EMF, etc.). That inductive behavior means they aren’t pure resistive loads. So, the component that is most clearly a resistive load when powered is the light bulb.

A resistive load converts electrical energy to heat (and light in a bulb) with current that follows Ohm’s law: the current is proportional to the applied voltage and there’s little to no energy stored in the form of a magnetic or electric field. A standard automotive light bulb fits this behavior well—its filament simply resists the flow of current, heating up to emit light, with its resistance remaining relatively constant during normal operation.

In contrast, the starter motor, the relay coil, and fuel injectors rely on magnetic fields created by coils. These are inductive loads, which store energy in the magnetic field and cause current to lag behind voltage and to change as the device operates (start-up surge, back-EMF, etc.). That inductive behavior means they aren’t pure resistive loads.

So, the component that is most clearly a resistive load when powered is the light bulb.

More practice questions