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NATE_CORE NEC 2023

NATE Core Practice Test 8

This practice test covers basic electrical concepts from the NATE Core exam blueprint, focused on Ohm's Law and circuit behavior. You will see questions on voltage, current, resistance calculations, how series and parallel circuits behave, and power calculations in watts.

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NATE Core

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Frequently Asked Questions

Yes — completely free with no signup required. Every question includes a full explanation of the correct answer.

Two: the NATE Core exam plus at least one specialty exam (for example AC Service, Heat Pump Service, or Air Distribution Service). You can take them on the same day or separately.

The Core exam has 50 questions and each installation or service specialty exam has 100 questions. You need 70% on each to pass — 35 of 50 on Core and 70 of 100 on a specialty. Check natex.org for the current format before you book.

NATE certification lasts two years. To renew, you submit 16 hours of continuing education or retake the specialty exam before your certification expires.

No. These are independent practice tests written to match the published NATE exam topics. They are not official NATE exam questions.

Exam Tip: Memorize the Ohm's Law triangle: V = I × R, I = V ÷ R, R = V ÷ I. Also remember: series circuits share one path, parallel circuits offer multiple paths.

30

Questions

30 min

Time

70%

Pass

Timer starts immediately. Progress is auto-saved.

NATE Core Practice Test 8 — Question List

Question 1: Which formula correctly expresses Ohm's Law?

V = I ÷ R
R = I × V
I = R ÷ V
V = I × R

Question 2: A circuit has 120 volts and 24 ohms of resistance. What is the current?

5 amps
2 amps
10 amps
48 amps

Question 3: A circuit has 3 amps of current flowing through 40 ohms of resistance. What is the voltage?

13.3 volts
120 volts
43 volts
37 volts

Question 4: A circuit has 240 volts and 10 amps of current. What is the resistance?

250 ohms
2,400 ohms
24 ohms
230 ohms

Question 5: In a series circuit, how does current behave throughout the circuit?

Current is different at every point in the circuit
Current only flows at the very end of the circuit
Current splits evenly between each component
Current stays the same throughout the entire circuit

Question 6: In a series circuit, what happens if one component fails and creates an open circuit?

The entire circuit stops working because there is only one path for current
Only that component stops working, everything else still runs
The circuit automatically reroutes power
The voltage doubles at every other component

Question 7: In a parallel circuit, how does voltage behave across each branch?

Voltage is different across every branch
Voltage is the same across each parallel branch
Voltage only exists in the main branch
Voltage splits evenly between each branch

Question 8: In a parallel circuit, how does current behave as it flows through the different branches?

Current only flows through one branch at a time
Current is exactly the same in every branch, no matter the resistance
Current splits between the different branches
Current does not flow in a parallel circuit

Question 9: In a parallel circuit, if one branch fails and creates an open circuit, what happens to the other branches?

All branches stop working, just like a series circuit
The voltage on the other branches drops to zero
The other branches lose their power source entirely
The other branches continue to work normally, since they have their own separate path

Question 10: What does voltage measure in an electrical circuit?

The electrical pressure or force that pushes current through a circuit
The rate of current flow
The opposition to current flow
The physical size of a wire

Question 11: What does current measure in an electrical circuit?

The electrical pressure pushing electrons
The rate of flow of electrons through a circuit
The opposition to electron flow
The physical length of the wire

Question 12: What does resistance measure in an electrical circuit?

The rate of current flow
The electrical pressure pushing current
The opposition to the flow of current
The total power used by a circuit

Question 13: A circuit has 208 volts and 8 ohms of resistance. What is the current?

16 amps
20 amps
2 amps
26 amps

Question 14: A circuit has 120 volts and 4 amps of current. What is the resistance?

30 ohms
480 ohms
124 ohms
40 ohms

Question 15: A circuit has 12 amps of current flowing through 10 ohms of resistance. What is the voltage?

0.83 volts
120 volts
22 volts
100 volts

Question 16: A 12-ohm resistor and a 6-ohm resistor are connected in parallel. What is the total resistance?

4 ohms
18 ohms
9 ohms
2 ohms

Question 17: Three 30-ohm heater elements are wired in parallel across 240 volts. What is the total current?

8 amps
2.7 amps
72 amps
24 amps

Question 18: A 240-volt electric heater draws 20 amps. How much power does it use?

12 watts
260 watts
4,800 watts
2,400 watts

Question 19: If voltage stays the same but resistance in a circuit increases, what happens to the current?

Current increases
Current decreases
Current stays exactly the same
Current becomes impossible to calculate

Question 20: In a series circuit with multiple resistors, how is the total resistance found?

By taking the average of all the resistors
By multiplying the resistance of each resistor
By adding up the resistance of each resistor
Total resistance cannot be found in a series circuit

Question 21: A series circuit has two resistors: one at 15 ohms and one at 25 ohms. What is the total resistance?

10 ohms
375 ohms
20 ohms
40 ohms

Question 22: Three light bulbs are wired in series, and one bulb burns out (creating an open circuit). What happens to the other two bulbs?

They also turn off, because the circuit is broken
They stay on, but dimmer than before
They get brighter to compensate
Only the bulb closest to the power source stays on

Question 23: Three light bulbs are wired in parallel, and one bulb burns out (creating an open circuit) in its branch. What happens to the other two bulbs?

They also turn off, because the circuit is broken
They stay on normally, since each bulb has its own separate path
They flicker randomly
They get dimmer permanently

Question 24: Older-style holiday lights, where the entire string goes dark if one bulb burns out, are wired in what kind of circuit?

Neither series nor parallel
Parallel circuit
Series circuit
A circuit with no current at all

Question 25: In a home, why are most branch circuits and outlets wired in parallel rather than in series?

Parallel wiring is required to reduce voltage to zero
So that all outlets share exactly the same current
So that only one outlet in the house can be used at a time
So that a failure in one device or outlet does not shut off power to the others

Question 26: A current of 5 amps flows through a 10-ohm resistance. How much power is turned into heat?

50 watts
2 watts
250 watts
500 watts

Question 27: A 24-volt circuit has a 2-ohm and a 4-ohm resistance in series. What is the voltage drop across the 4-ohm resistance?

8 volts
16 volts
12 volts
24 volts

Question 28: A low-voltage control circuit has 24 volts and 6 ohms of resistance. What is the current?

30 amps
18 amps
4 amps
144 amps

Question 29: What is the key difference between how series and parallel circuits are wired?

Series circuits use no wires at all
Parallel circuits never use resistors
There is no real difference between the two
A series circuit has one single path for current; a parallel circuit has multiple paths

Question 30: True or False: In a parallel circuit, each branch always has the same voltage as the source.

True
False, voltage is always different in each branch
False, only current is the same across branches
False, voltage cannot be measured in a parallel circuit

EXAM CARD NATE_CORE

Questions30

Time limit30 min

Pass score70%

Code editionNEC 2023

DifficultyIntermediate

Last reviewedJun 2026

Timer starts immediately. Progress is auto-saved.

Source: NEC 2026 (NFPA 70)