IBEW Aptitude Test — Questions and Answers

Question 1: The power in a circuit is P = V²/R. If V = 120 and R = 60, what is P?

120 watts
240 watts (Correct answer)
300 watts
180 watts

Correct answer: 240 watts

P = 120² / 60 = 14400 / 60 = 240 watts.

Question 2: Use the quadratic formula to solve: x² - 4x - 5 = 0

x = 5 and x = -1 (Correct answer)
x = 5 and x = 1
x = -5 and x = 1
x = 4 and x = -1

Correct answer: x = 5 and x = -1

a=1, b=-4, c=-5. Discriminant=16+20=36. x=(4±6)/2. x=5 or x=-1.

Question 3: Which word is the antonym (opposite) of HAZARDOUS?

Risky
Dangerous
Unstable
Safe (Correct answer)

Correct answer: Safe

HAZARDOUS means dangerous or likely to cause harm. Its direct opposite is SAFE, meaning free from danger or risk.

Question 4: An electrician is installing light fixtures in a hallway. The fixtures are placed at the following distances from the start of the hallway (in feet): 4, 11, 18, 25. If this pattern continues, what is the distance of the next fixture?

32 feet (Correct answer)
35 feet
30 feet
33 feet

Correct answer: 32 feet

This is an arithmetic sequence. The distance between each fixture is constant. 11 - 4 = 7; 18 - 11 = 7; 25 - 18 = 7. The pattern is to add 7 feet for each subsequent fixture. Therefore, the next fixture will be at 25 + 7 = 32 feet.

Question 5: A passage reads: 'The National Electrical Code requires that all electrical installations be inspected and approved by the authority having jurisdiction prior to being placed in service.' Which term describes 'the authority having jurisdiction'?

The lead electrician on the project
The project owner or building manager
The organization or official responsible for enforcing code (Correct answer)
The equipment manufacturer's representative

Correct answer: The organization or official responsible for enforcing code

'Authority having jurisdiction' (AHJ) is a standard NEC term referring to the organization, office, or individual responsible for enforcing the requirements of a code.

Question 6: A scale drawing uses a scale of 1 inch = 4 feet. If a wall is 9 inches on the drawing, how long is the actual wall?

13 ft
72 ft
36 ft (Correct answer)
45 ft

Correct answer: 36 ft

Actual length = 9 inches × 4 ft/inch = 36 ft.

Question 7: A 12-volt battery is connected to a light bulb through a switch. The circuit is open (switch off). What is the voltage across the switch?

6 volts
Undefined
0 volts
12 volts (Correct answer)

Correct answer: 12 volts

In an open circuit no current flows, so there is no voltage drop across the bulb; all 12 V appears across the open switch.

Question 8: An apprenticeship handbook states: 'Apprentices must complete a minimum of 8,000 hours of on-the-job training and 900 hours of related classroom instruction to be eligible for journeyman status.' An apprentice has 7,500 OJT hours and 950 classroom hours. What is their status?

Not eligible, because both requirements must be met simultaneously
Not eligible, because OJT hours are below the 8,000-hour requirement (Correct answer)
Eligible, because the total combined hours exceed 8,900
Eligible, because classroom hours exceed the minimum

Correct answer: Not eligible, because OJT hours are below the 8,000-hour requirement

Both requirements must be met independently; 7,500 OJT hours falls short of the 8,000-hour minimum.

Question 9: A contract document reads: 'The contractor shall furnish all labor, materials, equipment, and incidentals necessary for the complete installation of the electrical system as shown on the drawings and specified herein.' The word 'incidentals' most likely refers to:

Incidents and accidents that occur on the job site
Minor items not explicitly listed but needed for completion (Correct answer)
Electrical incidents such as arc flash events
Accidental damage caused during installation

Correct answer: Minor items not explicitly listed but needed for completion

In contract language, 'incidentals' refers to minor items and miscellaneous materials not specifically listed but required to complete the work.

Question 10: A safety manual states: 'All workers must de-energize and lock out equipment before performing maintenance, unless the task requires the equipment to be energized, in which case appropriate PPE must be worn.' A technician needs to lubricate a moving conveyor belt. What does the manual require?

Wear PPE and lubricate while the belt is running
Get supervisor approval before any action
Lubricate only during scheduled downtime
De-energize and lock out the belt before lubricating (Correct answer)

Correct answer: De-energize and lock out the belt before lubricating

Lubrication of a moving belt does not require it to be energized, so de-energize and lock out applies.

Question 11: In a parallel circuit with two 10Ω resistors, what is the total resistance?

20Ω
0.5Ω
5Ω (Correct answer)
10Ω

Correct answer: 5Ω

For two equal resistors in parallel, total resistance = R/2, so 10Ω ÷ 2 = 5Ω.

Question 12: Find the sum of the arithmetic series: 5 + 8 + 11 + 14 + 17 (first 5 terms).

45
55 (Correct answer)
60
50

Correct answer: 55

Sum = n/2 × (a_1 + a_n) = 5/2 × (5 + 17) = 2.5 × 22 = 55.

Question 13: Which method is best for factoring x³ - 27?

Trinomial method
Difference of squares
Grouping
Difference of cubes (Correct answer)

Correct answer: Difference of cubes

x³ − 27 = x³ − 3³ is a difference of cubes, factored as (x − 3)(x² + 3x + 9).

Question 14: Simplify: 4(2x - 3) - 2(x + 5)

8x - 22
6x + 2
6x - 22 (Correct answer)
6x - 2

Correct answer: 6x - 22

8x - 12 - 2x - 10 = 6x - 22.

Question 15: If f(x) = 2x² - 3x + 1, find f(-1).

2
8
6 (Correct answer)
4

Correct answer: 6

f(-1) = 2(-1)² - 3(-1) + 1 = 2 + 3 + 1 = 6.

Question 16: Factor: x² - x - 12

(x + 6)(x - 2)
(x - 6)(x + 2)
(x - 3)(x + 4)
(x + 3)(x - 4) (Correct answer)

Correct answer: (x + 3)(x - 4)

Find two numbers with product=-12, sum=-1: -4 and +3. Factor: (x+3)(x-4).

Question 17: Find the 10th term of the arithmetic sequence: 5, 8, 11, 14, ...

29
35
32 (Correct answer)
30

Correct answer: 32

a_n = a_1 + (n-1)d = 5 + (10-1)×3 = 5 + 27 = 32.

Question 18: Solve for x: 7x + 3 = 4x + 18

x = 5 (Correct answer)
x = 6
x = 3
x = 4

Correct answer: x = 5

7x - 4x = 18 - 3 → 3x = 15 → x = 5.

Question 19: Add the polynomials: (3x² - 2x + 5) + (x² + 4x - 3)

3x² + 2x + 2
4x² + 2x - 2
4x² - 2x + 2
4x² + 2x + 2 (Correct answer)

Correct answer: 4x² + 2x + 2

Combine like terms: (3x²+x²) + (-2x+4x) + (5-3) = 4x² + 2x + 2.

Question 20: A movable pulley system has 2 rope segments supporting the load. What is the mechanical advantage?

2 (Correct answer)
1
4
3

Correct answer: 2

Mechanical advantage = number of rope segments supporting the load = 2.

Question 21: The ratio of the length to width of a rectangular electrical panel cover is 5:2. If the width is 14 inches, what is the length?

40 inches
28 inches
35 inches (Correct answer)
30 inches

Correct answer: 35 inches

Using the proportion 5/2 = x/14 gives x = (5 × 14) / 2 = 35 inches.

Question 22: An apprentice correctly terminates 45 out of 50 wires in a control panel. What percentage of the wires were terminated correctly?

95%
90% (Correct answer)
85%
45%

Correct answer: 90%

To find the percentage, create a fraction of the correctly terminated wires over the total number of wires, which is 45/50. To convert this fraction to a percentage, divide the numerator by the denominator (45 ÷ 50 = 0.9) and then multiply the result by 100 (0.9 * 100 = 90%).

Question 23: A safety bulletin states: 'Lockout/Tagout procedures must be followed when performing maintenance on electrical equipment. A lockout device physically prevents the energy source from being re-energized, while a tagout device only provides a warning.' Based on this, which provides MORE protection?

Both provide equal protection in all situations
Tagout, because it warns all workers
Neither; both must always be used together by law
Lockout, because it physically prevents re-energization (Correct answer)

Correct answer: Lockout, because it physically prevents re-energization

The passage explicitly states that a lockout device physically prevents re-energization, making it more protective than a tagout device which only provides a warning.

Question 24: If f(x) = 4x - 3 and g(x) = x + 5, what is f(g(2))?

26
29
25 (Correct answer)
22

Correct answer: 25

g(2) = 2 + 5 = 7. f(7) = 4(7) - 3 = 28 - 3 = 25.

Question 25: A technical manual states: 'Before energizing any circuit, the technician must verify that all grounding conductors are properly connected and that no personnel are within the restricted zone.' What is the PRIMARY purpose of this instruction?

To identify grounding conductor types
To ensure safety before applying power (Correct answer)
To document circuit configurations
To speed up the energizing process

Correct answer: To ensure safety before applying power

The instruction lists two safety preconditions (grounding and personnel clearance) that must be met before energizing, making worker safety the primary purpose.

Question 26: Solve: x² + 3x - 10 = 0

x = 2 and x = -5 (Correct answer)
x = -2 and x = 5
x = -2 and x = -5
x = 2 and x = 5

Correct answer: x = 2 and x = -5

Factor: (x+5)(x-2)=0. x=-5 or x=2.

Question 27: Factor: x² - 16

(x - 4)(x + 4) (Correct answer)
(x - 8)(x + 2)
(x - 4)²
(x + 16)(x - 1)

Correct answer: (x - 4)(x + 4)

Difference of squares: x² - 4² = (x-4)(x+4).

Question 28: Solve for y: 5y + 3 = 3y + 11

y = 7
y = 4 (Correct answer)
y = 1
y = 2

Correct answer: y = 4

Subtract 3y from both sides: 2y + 3 = 11, then subtract 3 and divide: y = 4.

Question 29: Two meshed gears have a speed ratio of 3:1. If the smaller (faster) gear has 15 teeth, how many teeth does the larger gear have?

60 teeth
50 teeth
30 teeth
45 teeth (Correct answer)

Correct answer: 45 teeth

Speed ratio 3:1 means the small gear spins 3 times for every 1 revolution of the large gear. Tooth ratio is inverse: 1:3. Larger gear teeth = 15 × 3 = 45.

Question 30: Solve the following system of equations for y: 2x + y = 11 3x - 2y = 6

y = 11
y = -1
y = 4
y = 3 (Correct answer)

Correct answer: y = 3

One way to solve this is using the substitution method. First, solve the top equation for y: y = 11 - 2x. Now, substitute this expression for y into the second equation: 3x - 2(11 - 2x) = 6. Distribute the -2: 3x - 22 + 4x = 6. Combine like terms: 7x - 22 = 6. Add 22 to both sides: 7x = 28. Solve for x: x = 4. Finally, substitute x = 4 back into the first equation: 2(4) + y = 11, which simplifies to 8 + y = 11. Solving for y gives y = 3.

Question 31: Factor: 3x² - 12x

3(x² - 4x)
12x(x - 1)
3x(x - 4) (Correct answer)
x(3x - 12)

Correct answer: 3x(x - 4)

GCF of 3x² and 12x is 3x. 3x² ÷ 3x = x, 12x ÷ 3x = 4. Factored: 3x(x - 4).

Question 32: If g(x) = x/3 + 4, what is g(12)?

8 (Correct answer)
7
6
9

Correct answer: 8

g(12) = 12/3 + 4 = 4 + 4 = 8.

IBEW Aptitude Test

The IBEW Aptitude Test evaluates electrical knowledge, algebra, and reading comprehension for union electrician apprenticeship.

Questions

46 min

Time Limit

65%

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