All Practice Exams
100+ Free Cert III Auto Electrical Practice Questions
Certificate III in Automotive Electrical Technology (AUR30320) practice questions are available now; exam metadata is being verified.
✓ No registration✓ No credit card✓ No hidden fees✓ Start practicing immediately
100+ Questions
100% Free
Loading practice questions...
Same family resources
Explore More Australian Trade Licences & Certificate III
Continue into nearby exams from the same family. Each card keeps practice questions, study guides, flashcards, videos, and articles in one place.
2026 Statistics
Key Facts: Cert III Auto Electrical Exam
100
Practice Questions
OpenExamPrep
32
Units of Competency
training.gov.au
Competency
Assessment Type
ASQA
3 years
Typical Apprenticeship
Australian Apprenticeships
The Certificate III in Automotive Electrical Technology (AUR30320) is Australia's trade qualification for auto electricians. Assessed unit-by-unit across 32 units, it spans circuit diagnostics, battery/starting/charging systems, engine management sensors, networking (CAN/LIN), body control modules, and hybrid/EV high-voltage safety. This prep includes 100 trade-theory practice questions.
Sample Cert III Auto Electrical Practice Questions
Try these sample questions to test your Cert III Auto Electrical exam readiness. Each question includes a detailed explanation. Start the interactive quiz above for the full 100+ question experience with AI tutoring.
1An automotive technician needs to find the resistance of an auxiliary lighting circuit. If the circuit is connected to a 12V source and draws a current of 2A, what is the resistance?
A.6 ohms
B.24 ohms
C.0.16 ohms
D.10 ohms
Explanation: According to Ohm's Law (R = V / I), the resistance is calculated by dividing the voltage by the current. In this case, 12V divided by 2A equals 6 ohms. Knowing this value helps in selecting the correct wire gauge and fuse size.
2Which of the following describes the correct procedure for measuring a voltage drop across a load?
A.Connect the voltmeter in series with the load with the circuit powered.
B.Connect the voltmeter in parallel with the load with the circuit powered.
C.Connect the ohmmeter in parallel with the load with the power disconnected.
D.Connect the ammeter in parallel with the load with the circuit powered.
Explanation: A voltage drop test measures the difference in electrical potential across a component or connection. The voltmeter must be connected in parallel (across the component) while the circuit is active and current is flowing. If the circuit is not active, no voltage drop will occur.
3When using an oscilloscope to capture a waveform from a wheel speed sensor, what electrical parameter does the vertical axis (Y-axis) represent?
A.Time
B.Current
C.Voltage
D.Frequency
Explanation: An oscilloscope plots electrical signals over time. The vertical axis (Y-axis) represents voltage, allowing the technician to see changes in signal amplitude. The horizontal axis (X-axis) represents time.
4What is the total resistance of two 6-ohm auxiliary lights connected in parallel to a vehicle's battery?
A.12 ohms
B.3 ohms
C.1.5 ohms
D.36 ohms
Explanation: For parallel circuits with identical resistors, the total resistance (Rt) is the resistance of one component divided by the number of components (Rt = R / n). Here, Rt = 6 / 2 = 3 ohms. Alternatively, 1/Rt = 1/6 + 1/6 = 2/6, so Rt = 6/2 = 3 ohms.
5A series diagnostic test circuit consists of three resistors: 4 ohms, 6 ohms, and 12 ohms. What is the total circuit resistance?
A.2 ohms
B.22 ohms
C.24 ohms
D.1.8 ohms
Explanation: In a series circuit, total resistance (Rt) is the sum of all individual resistances: Rt = R1 + R2 + R3. Therefore, 4 + 6 + 12 = 22 ohms.
6An automotive circuit has a 2-ohm resistor. If a technician measures a current of 4A flowing through this resistor, what is the voltage drop across it?
A.8V
B.2V
C.0.5V
D.16V
Explanation: Ohm's Law states that voltage drop (V) is current (I) multiplied by resistance (R): V = I * R. Therefore, 4A * 2 ohms = 8V.
7A 12V halogen fog lamp draws 5A of current. How much electrical power is dissipated by the lamp?
A.2.4W
B.17W
C.60W
D.0.41W
Explanation: Electrical power (P) is calculated by multiplying voltage (V) by current (I): P = V * I. In this case, 12V * 5A = 60 Watts.
8A distribution block connects three parallel branches. Each branch contains a 12-ohm heating element. What is the total equivalent resistance of this circuit?
A.36 ohms
B.4 ohms
C.6 ohms
D.3 ohms
Explanation: For parallel circuits with equal resistances, Rt = R / n. With three 12-ohm resistors in parallel, Rt = 12 / 3 = 4 ohms. Using the formula: 1/Rt = 1/12 + 1/12 + 1/12 = 3/12 = 1/4, so Rt = 4 ohms.
9What is the correct configuration for using a digital multimeter (DMM) to measure current draw in a circuit?
A.Connect the meter in parallel with the load with the power on.
B.Connect the meter in series with the load with the power on.
C.Connect the meter in series with the load with the power off.
D.Connect the meter in parallel with the load with the power off.
Explanation: To measure current (amperage), the multimeter must be connected in series with the load, allowing all circuit current to flow through the meter. The circuit must be powered and operating for current to flow.
10What is the maximum acceptable voltage drop across a battery ground cable during an engine cranking test?
A.0.2V
B.0.5V
C.1.0V
D.2.0V
Explanation: For a heavy-duty starting circuit cable, the standard maximum acceptable voltage drop is 0.2V. High resistance in ground cables can cause slow cranking, hard starting, and module communication issues.
About the Cert III Auto Electrical Practice Questions
Verified exam format metadata for Certificate III in Automotive Electrical Technology (AUR30320) is pending. The practice questions above remain available while official exam length, timing, passing score, fee, and administrator details are reviewed.