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The EEI POSS Test (Plant Operator Selection System) is a pre-employment cognitive assessment developed and owned by the Edison Electric Institute (EEI) to evaluate candidates for power plant operator roles at nuclear, hydroelectric, and fossil fuel power plants across U.S. investor-owned electric utilities. It is one of the core EEI pre-employment assessments used in the energy sector.
Key facts about the POSS test:
* The EEI POSS Test is developed and owned by the Edison Electric Institute (est. 1933), the trade association representing all U.S. investor-owned electric companies. The test is administered directly by member utility employers or at approved third-party testing centers. It is not available online.
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Here you'll find a free EEI POSS practice test organized into 4 sections: Reading Comprehension, Mechanical Concepts, Mathematical Usage, and Figural Reasoning. Each section includes questions, answers, and helpful tips. The questions are sourced from JobTestPrep's preparation materials and are similar to those on the actual POSS exam.
In the long version of the mathematical usage section, you'll have 17 minutes to answer 46 questions. This test is made up of three parts, including formula conversion problems, algebra problems, and word problems.
X + 14.9 = 7.6, X =?
Wrong
Wrong
Wrong
Correct!
Wrong
The correct answer is (D) -7.3.
This is a single-variable equation, meaning our goal is to isolate x.
To isolate a variable, move all numbers away from it by performing the same operation on both sides of the equation.
Here, subtract 14.9 from both sides: X + 14.9 - 14.9 = 7.6 - 14.9
This simplifies to: X = -7.3. So, the final value of X is -7.3.

5 miles/minute = ? feet/second conversion table
Wrong
Wrong
Wrong
Correct!
Wrong
The correct answer is (D) 440.
We are converting miles per minute to feet per second.
From the given information: 1 mile/minute = 88 feet/second
To find how many feet/second are in 5 miles/minute, use proportional reasoning:
1 mile/minute → 88 feet/second
5 miles/minute → x feet/second
Set up the proportion: x = (5 × 88) ÷ 1
x = 440. Therefore, 5 miles/minute = 440 feet/second.
6n² + 6 = 60 n = ?
Wrong
Wrong
Wrong
Correct!
The correct answer is (D) 3.
Start with the equation: 6n² + 6 = 60
Subtract 6 from both sides: 6n² = 54
Divide both sides by 6: n² = 9
Take the square root of both sides: n = 3
Therefore, the correct answer is 3.
Wrong
Wrong
Correct!
Wrong
The correct answer is (C).
Start with the formula: L = R / G
To isolate G, first eliminate the denominator by multiplying both sides by G:
LG = R
Now divide both sides by L to solve for G: G = R / L
Therefore, the correct answer is (C).
In this section of the POSS test, you'll have 20 minutes to answer 44 multiple-choice questions. There are many different mechanical concepts being tested here, including Centrifugal Force, Gears, Gravity, Levers, Pulleys, and Shapes.
In which of the following positions would the tractor be less stable when taking a turn?
Wrong
Correct!
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The correct answer is (B).
The only difference between the two figures is the position of the tractor’s shovel.
In Figure A, the shovel is lowered. In Figure B, the shovel is raised.
Raising the shovel increases the height of the tractor’s center of mass.
When the center of mass is higher, an object becomes less stable.
For example, a tall semi-trailer is less stable than a low sports car because its center of mass is higher.
Since Figure B has the shovel raised, it is less stable.
Therefore, the correct answer is (B).
If the left cogwheel rotates in the direction of the arrow, in which direction does the right wheel rotate?
Correct!
Wrong
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The correct answer is (A).
Cogwheels that touch each other rotate in opposite directions.
If the left wheel turns counterclockwise, the middle wheel must turn clockwise.
Since the right wheel touches the middle wheel, it will again rotate in the opposite direction, which is counterclockwise. Therefore, the answer is 1.
At which point does the ball have a greater velocity? (If equal, Mark C.)?
Wrong
Correct!
Wrong
The ball is under the influence of gravity, which causes a constant acceleration downward.
Acceleration means the ball’s speed increases as it moves.
Since the ball continues accelerating while falling, its velocity at point B is greater than at point A.
Remember: A freely falling object keeps speeding up as long as gravity is acting on it. Therefore, the correct answer is (B).
In this section of the POSS exam, you have 10 minutes to answer 20 figural reasoning questions, where you will need to identify patterns to solve problems. The test includes three types of questions: Picture Series, Picture Comparison, and Picture Progression. Here is an example of a Picture Series question.
X is to Y as Z is to ?
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Correct!
Wrong
Wrong
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The correct answer is (B).
The only difference between the two figures is the position of the tractor’s shovel.
In Figure A, the shovel is lowered. In Figure B, the shovel is raised.
Raising the shovel increases the height of the tractor’s center of mass.
When the center of mass is higher, an object becomes less stable.
For example, a tall semi-trailer is less stable than a low sports car because its center of mass is higher.
Since Figure B has the shovel raised, it is less stable.
Therefore, the correct answer is (B).
Identify the next figure in the series
Correct!
Wrong
Wrong
Wrong
Wrong
Down each column, the sun’s center color stays the same. Since the missing frame is in the right column where the centers are always white, the missing center must be white, so we can eliminate choice 3.
Across each row, the pattern connects the center and the rays. In the bottom row, the diagonal rays (pointing to the corners) match the center color. So the missing frame must have diagonal rays that match its white center, eliminating choices 4 and 5.
Finally, we do not repeat the same ray color combination within a row or column. Choice 2 repeats an existing blue-and-white ray combination, so it is eliminated.
The only option that fits all rules is choice 1.
Identify the next figure in the series
Wrong
Wrong
Correct!
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Wrong
Use the top row to find the pattern across the row.
Left → middle: the two side triangles flip inward toward the center (like folding flaps). Middle → right: the entire middle frame is rotated 180° (half-turn).
Apply the same pattern to the bottom row. The bottom-left already flips inward to make the bottom-middle, so the missing bottom-right must be a 180° rotation of the bottom-middle frame.
In the bottom-middle frame:
Left triangle: top yellow, bottom white
Right triangle: top blue, bottom yellow
After a 180° rotation, we should see:
Left triangle: top yellow, bottom blue
Right triangle: top white, bottom yellow
Only choice 3 matches this, so the answer is 3.
In this section of the test, you have 30 minutes to answer 36 multiple-choice questions. You are presented with five different passages, and for each passage, you have to answer a number of different questions.
These passages are generally excerpts from power plant operator training and safety manuals.
"Just as the sun’s rays can be focused by a magnifying glass to burn a piece of paper, high-intensity ultrasound waves can be concentrated to burn human tissue. The waves are harmless until they converge at the focal point, so a surgeon can operate deep inside the body without harming the surrounding tissue. HIFU requires no cuts to be made, and many operations don’t even need an anesthetic, so the patient can be in and out of the hospital within a day".
How can HIFU enable early release of patients from hospital?
Wrong
Wrong
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Correct!
Choices (A) and (B) are mentioned in the passage, but they are not given as the reason for early discharge.
Choice (C) is incorrect because the passage states that the waves are harmless until they converge at the focal point, meaning they are not always harmless.
The final sentence of the passage explains why HIFU allows early release:
“HIFU requires no cuts to be made, and many operations don’t even need an anaesthetic, so the patient can be in and out of hospital within a day.”
This directly supports choice (D).
The Invention of the Light Bulb
"The development of the light bulb is one of the most significant milestones in the history of electricity. Thomas Edison is often credited with the invention of the first practical incandescent light bulb, but the journey to this invention involved many inventors and years of experimentation.
In 1800, Alessandro Volta invented the first electrical battery, known as the voltaic pile, which could produce a steady current of electricity. This invention laid the groundwork for future electrical devices. Humphry Davy, in 1802, created the first electric lamp by connecting voltaic piles to charcoal electrodes, producing a bright arc of light. However, Davy's arc lamp was too intense and impractical for home use.
The next significant advancement came in 1841, when Frederick de Moleyns patented a bulb filled with a vacuum, containing platinum filaments that glowed when electric current passed through them. Despite this advancement, the platinum filaments were costly and inefficient.
Thomas Edison, through extensive experimentation, developed a carbon filament that could glow for hours when heated by an electric current, leading to the creation of a long-lasting and practical incandescent light bulb. On October 21, 1879, Edison's bulb burned for 13.5 hours, a significant improvement over previous designs.
Edison's success was due not only to the invention of the bulb but also to the development of a complete electrical distribution system, which made the widespread use of electric lighting feasible. This system included generators, wiring, and the first commercial power station.
Edison's work laid the foundation for modern electric lighting and power distribution, making it possible for homes and cities to be illuminated by electric light".
In the development of the light bulb, who invented the first electric lamp by connecting voltaic piles to charcoal electrodes?
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Correct!
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The passage states: “Humphry Davy, in 1802, created the first electric lamp by connecting voltaic piles to charcoal electrodes, producing a bright arc of light.”
This clearly shows that Humphry Davy invented the first electric lamp using this method.
The other individuals mentioned had different contributions:
• Alessandro Volta invented the first electrical battery.
• Frederick de Moleyns patented a bulb using platinum filaments.
• Thomas Edison developed the practical incandescent light bulb with a carbon filament.
Therefore, the correct answer is (B).
A GHG tax can be levied at any point in the energy supply chain. Most proposals target upstream suppliers of coal, oil, and natural gas as opposed to midstream points (electric utilities or oil refineries) and downstream (energy-using industries, households). Measuring the carbon content of fuels is a straightforward task and there are relatively fewer fuel producers and importers. To be fully inclusive, a downstream tax would have to fall on millions of users, increasing the likelihood that the program's scope would be more limited with higher aggregate and administrative costs".
Why not tax downstream users?
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Correct!
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The passage says a downstream tax has higher aggregate and administrative costs.
This matches choice (B).
Using our EEI POSS Test PrepPack, you get:
We've created a comprehensive EEI POSS test prep course designed to help you succeed. Our course closely mimics the actual test conditions and platform, allowing you to identify and improve your weaker areas. With this focused preparation, you'll be confident and ready to excel on test day.
Why preparation matters: Most utilities enforce a 30-day minimum waiting period between retake attempts and limit candidates to 2 attempts per 12-month period. There is no second chance to make a first impression - thorough preparation before your first attempt is not optional, it is essential.
JobTestPrep's EEI POSS test prep has recently been upgraded based on expert research and user feedback in order to ensure that you receive the highest quality practice available. You can rely on our experience and expertise to provide you with the tools you need to get the high score you need.
At JobTestPrep, we've helped thousands of candidates pass competitive hiring assessments since 1992. Our materials are designed by psychometric experts and updated based on real candidate feedback to reflect the latest test formats.
Hi, I'm Yedidya Lixenberg. I hold a B.A. in Psychology and am currently pursuing an M.A. in Organizational Psychology with a focus on psychometric assessment and testing methodology. I've been with JobTestPrep since 2020, where I've developed deep expertise in energy industry pre-employment assessment preparation, helping thousands of candidates master EEI aptitude tests and secure skilled trades and technical roles at major U.S. electric utilities.
My specialized knowledge of mechanical and cognitive aptitude testing - particularly Graphic Arithmetic, Mathematical Usage, Mechanical Concepts, and Reading Comprehension as they apply to lineman, substation, and construction and skilled trades roles - directly informs the EEI preparation materials on this page. I've worked extensively with the cognitive frameworks underlying EEI's assessment design, studying how utilities like ComEd, Georgia Power, PECO, Ameren, PSEG, and AEP deploy the CAST test to evaluate candidate readiness for field and technical positions. This expertise allows me to create realistic practice materials that mirror the exact demands and question patterns of the official EEI assessment.
My approach combines psychometric rigor with practical knowledge of what utility employers are actually testing for - ensuring that every practice question teaches you not just the correct answer, but the mechanical reasoning and problem-solving logic you'll need on test day and in your future role.
Have a question? Contact me at:
There is no universal passing score for the POSS test. Your raw scores across the four sections are combined into an overall Aptitude Index ranging from 0 to 15, where a higher score reflects a stronger predicted likelihood of success in plant operations. Each utility sets its own cutoff independently, and most employers notify candidates of a pass or fail result rather than disclosing the exact score or cutoff threshold.
Retake policies vary by employer - each utility sets its own rules. Duke Energy, for example, requires candidates to wait 90 days between attempts. Entergy enforces a 30-day minimum and limits candidates to 2 attempts per 12-month period. Because retake opportunities are limited and tied to active job applications, there is rarely a second chance on a short timeline. Preparing thoroughly before your first attempt is essential.
The POSS test is not difficult in terms of content complexity - the questions themselves are based on high school level mathematics, mechanical principles, and reading comprehension. The real challenge is time. Each section is administered separately with its own strict time limit. The Mathematical Usage section is a particularly high-speed sprint, requiring you to answer 46 questions in just 17 minutes—less than 23 seconds per problem. While a handful of utilities may provide a basic calculator, the vast majority follow the official EEI standard which prohibits them, so you should prepare to solve everything manually. Many candidates do not finish this section. Preparing under timed conditions is the only reliable way to build the speed the test demands.
No. The POSS (Plant Operator Selection System) and the MASS (Power Plant Maintenance Positions Selection System) are two separate EEI assessments designed for different roles. The POSS evaluates candidates for plant operator positions. The MASS evaluates candidates for maintenance roles such as electricians, welders, pipe fitters, and steelworkers. Some utilities - including PSEG - administer both tests together in a combined POSS/MASS battery for candidates applying across both role families. If your job posting references both, expect a longer testing session of approximately three hours. We also recommend preparing for the MASS test separately.
The Plant Operator Selection System - commonly known as the POSS test or POSS exam - is a standardized cognitive battery created by the Edison Electric Institute (est. 1933) to screen candidates for power plant operator positions at U.S. electric utilities.
Power plant operators are responsible for monitoring and controlling the equipment and systems that generate electricity at nuclear, fossil fuel, and hydroelectric facilities - including boilers, turbines, generators, and reactor systems. The role requires the ability to read and interpret technical materials, perform accurate calculations under pressure, understand mechanical systems, and make fast, reliable decisions in safety-critical environments. A single operational error at a power plant can have serious consequences for grid stability, public safety, and the facility itself.
Because of this, utilities cannot rely on interviews or resumes alone to assess whether a candidate has the cognitive baseline the job demands. The POSS was developed in collaboration with EEI member utilities specifically to predict a candidate's probability of success in plant operations roles - measuring the four abilities most directly tied to job performance: Mathematical Usage, Mechanical Concepts, Reading Comprehension, and Figural Reasoning.
The test is not publicly available and is only administered through a hiring utility as part of an active job application process.
The POSS-C is a specific version of the Plant Operator Selection System used by certain utilities for particular plant operator classifications. It refers to a variant of the standard POSS battery - the letter designation typically indicates the test version administered by the specific utility rather than a different test altogether. If your hiring utility has told you that you will be taking the POSS-C, prepare using the same four-section format: Mathematical Usage, Mechanical Concepts, Figural Reasoning, and Reading Comprehension.
The core POSS test format and sections are the same regardless of plant type. However, utilities operating nuclear facilities - such as Exelon, TVA, and Dominion Energy - may apply higher cutoff scores given the safety-critical nature of nuclear plant operations. Some nuclear operators also supplement the POSS with additional plant-specific assessments or background screening requirements beyond what fossil fuel or hydroelectric employers require. The preparation approach remains the same: focus on speed and accuracy across all four sections.
You cannot register for the POSS test independently. The test is only available through a hiring utility as part of an active job application. Once you apply for a qualifying position and are selected for testing, the utility will contact you with instructions, a test date, and a testing location. You will typically need to bring a valid government-issued photo ID. A calculator is usually provided for the Mathematical Usage section, though policies vary by employer - confirm with your hiring utility before test day.
Results are typically communicated within one to two weeks of testing. Most utilities report outcomes as pass or fail rather than sharing your exact index score or section breakdown. Some employers - including those using on-site test administrators such as AECC - notify candidates of their result immediately after testing.
In most current versions of the POSS, your score is based solely on the number of correct answers - there is no penalty for wrong or unanswered questions. This means guessing is always preferable to leaving a question blank if time runs out. However, test administration policies can vary by employer and test version, so always follow the specific instructions given to you on test day.
POSS practice test PDFs are widely available online but have significant limitations. They are static, unverifiable, and almost always outdated - many circulate versions of the test that no longer reflect current question formats or difficulty levels. More critically, a PDF cannot simulate timed conditions, which is the single most important factor in POSS performance. The Mathematical Usage section gives you under 23 seconds per question. No PDF can train you for that. Effective POSS preparation requires timed, interactive practice tests that replicate the actual test environment section by section - which is exactly what the JobTestPrep POSS PrepPack provides.
Not reliably. While some utilities may have access to scores from previous testing, this is not guaranteed. Different utilities may administer different versions of the POSS, apply different cutoff thresholds, or simply require fresh testing as a matter of policy. Treat every new application as requiring a new test, and prepare accordingly regardless of any previous POSS experience.
After completing your payment, you will receive two emails: a payment receipt and a login link with your account details. Once you log in and reset your password, you will have instant, unlimited access to your PrepPack.
You can start practicing immediately with tailored questions and detailed explanations, tracking your performance along the way. Your progress is saved, allowing you to revisit previous attempts as many times as you like. If you need more time, you can extend your subscription by contacting c.serv@jobtestprep.com.
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