Plant Operator Selection System (POSS) Test

Use these POSS Plant Operator Selection System practice questions to review reading comprehension, mechanical concepts, mathematical usage, and figural reasoning skills. You’ll also find details about the test format, scoring, scheduling, costs, and study resources.

Test Type

Plant operator hiring assessment

Developer

Edison Electric Institute

Main Skill Areas

Reading, mechanical concepts, math, and figural reasoning

Testing Access

Scheduled through the hiring company

Exam Background and Purpose

The Plant Operator Selection System (POSS) test is a timed aptitude test battery developed by the Edison Electric Institute. Electric companies may use the POSS test to help evaluate candidates for plant operating positions in nuclear, hydropower, and fossil fuel power plants.

Job titles for plant operator positions may vary. The job posting, recruiter, or employer will usually tell you whether the POSS test is required as part of the hiring process.

Online POSS Prep Course

If you want to be fully prepared, Mometrix offers an online POSS Prep Course. The course is designed to provide you with the resources you need while studying. The POSS Course includes:

POSS Course Features

  • Review lessons covering every topic
  • 750 POSS practice questions
  • Over 30 instructional videos
  • Money-back guarantee
  • Free mobile access
  • and more!

The POSS Prep Course is designed to help learners get the review, practice, and study support they need before test day.


Start POSS Prep with Mometrix

What Is on the POSS Test?

Each test area evaluates a different skill that may be important for plant operator work. The exact version used may depend on the employer, so follow the instructions provided by the company that invited you to test.

POSS Test Areas

Reading Comprehension

36 questions / 30 minutes

Measures your ability to read workplace-style passages and answer questions based on the information provided.

Mechanical Concepts

44 questions / 20 minutes

Measures your understanding of basic mechanical principles and mechanical processes similar to those used in utility work.

Mathematical Usage

Timing varies by version

Measures your ability to use basic formulas, solve equations, work through word problems, and complete math quickly under time pressure.

Figural Reasoning

20 questions / 10 minutes

Measures your ability to identify patterns, compare images, and determine how figures change across a sequence.

Key point: the POSS is usually part of an employer’s hiring process. Your testing date, location, instructions, and required version will come from the company where you applied.

POSS Plant Operator Selection System Practice Questions

10 Sample Questions

Try these sample questions to review the types of skills measured by the POSS test. These questions are for general practice only.

Answer each question first, then open the answer explanation to check your work.

1. A safety notice says that a valve must be closed before maintenance begins. What should the operator do first?

  1. Begin maintenance and close the valve later
  2. Close the valve before maintenance begins
  3. Open the valve to check the pressure
  4. Ignore the notice if the equipment appears stable
Show Answer and Explanation

Answer: B. Close the valve before maintenance begins

The notice gives a required step before maintenance. The safest and most accurate answer follows the written instruction directly.

2. If Gear A turns clockwise and Gear B is directly meshed with Gear A, which direction will Gear B turn?

  1. Clockwise
  2. Counterclockwise
  3. It will not move
  4. The direction cannot be determined
Show Answer and Explanation

Answer: B. Counterclockwise

Two directly meshed gears rotate in opposite directions. If Gear A turns clockwise, Gear B turns counterclockwise.

3. Solve for x: 5x + 10 = 35.

  1. 3
  2. 4
  3. 5
  4. 7
Show Answer and Explanation

Answer: C. 5

Subtract 10 from both sides to get 5x = 25. Divide by 5 to get x = 5.

4. Which number comes next in the pattern? 3, 6, 12, 24, ___

  1. 30
  2. 36
  3. 42
  4. 48
Show Answer and Explanation

Answer: D. 48

Each number is doubled: 3 × 2 = 6, 6 × 2 = 12, 12 × 2 = 24, and 24 × 2 = 48.

5. A pump moves 12 gallons per minute. How many gallons will it move in 8 minutes?

  1. 20
  2. 72
  3. 84
  4. 96
Show Answer and Explanation

Answer: D. 96

Multiply the flow rate by the time: 12 gallons per minute × 8 minutes = 96 gallons.

6. In a simple pulley system, adding a movable pulley generally makes lifting a load require:

  1. less force
  2. more force
  3. no rope movement
  4. no change in direction or force
Show Answer and Explanation

Answer: A. less force

A movable pulley can provide mechanical advantage, which reduces the amount of force needed to lift the load.

7. A manual states that equipment temperature must be recorded every 30 minutes. If the first reading is taken at 8:00, when should the fourth reading be taken?

  1. 8:30
  2. 9:00
  3. 9:30
  4. 10:00
Show Answer and Explanation

Answer: C. 9:30

The first reading is at 8:00, the second at 8:30, the third at 9:00, and the fourth at 9:30.

8. Which value is equal to 3/4 of 80?

  1. 20
  2. 40
  3. 60
  4. 75
Show Answer and Explanation

Answer: C. 60

One-fourth of 80 is 20. Three-fourths is 20 × 3 = 60.

9. Which choice best completes the pattern? Circle, square, triangle, circle, square, ___

  1. circle
  2. square
  3. triangle
  4. rectangle
Show Answer and Explanation

Answer: C. triangle

The pattern repeats in groups of three: circle, square, triangle.

10. A tank contains 180 gallons of water. If 45 gallons are drained, what percent of the water remains?

  1. 25%
  2. 50%
  3. 75%
  4. 80%
Show Answer and Explanation

Answer: C. 75%

After 45 gallons are drained, 135 gallons remain. Then 135 ÷ 180 = 0.75, which is 75%.

Can I Use a Calculator?

The POSS test prohibits electronic devices such as calculators, cell phones, and similar devices. Follow the exact test-day instructions provided by the company administering your test.

How Is the POSS Test Graded?

The number of questions you answer correctly determines your score. The section scores are combined and evaluated on a scoring scale from 0 to 15, with 15 indicating a high probability of workplace success. There is no penalty for wrong or unanswered questions.

Can Other Electric Companies Use My Score?

Some applicants have found that another electric company could access a previous POSS score, but this is not guaranteed. It is best to prepare each time you apply for a plant operator position because employers may use different versions of the test or different score requirements.

Where and When Can I Take the POSS Test?

The POSS test is not scheduled independently like some standardized exams. It is usually offered through an electric company as part of the hiring process for an operating position. The company where you apply will provide the test date, time, location, and instructions.

How Much Does It Cost to Take the POSS Test?

Because the POSS test is generally offered as part of the hiring process for plant operator positions, candidates usually do not pay a separate testing fee.

How Can I Prepare for the POSS Test?

Preparing for the POSS test is easier when you understand the major skill areas and practice under timed conditions. Focus on reading carefully, solving math quickly, reviewing mechanical principles, and identifying visual patterns.

POSS Study Checklist

  • Review the test areas your employer tells you to expect.
  • Practice reading workplace-style passages quickly and accurately.
  • Review basic algebra, formulas, fractions, percentages, and word problems.
  • Practice basic mechanical concepts such as gears, pulleys, force, pressure, and motion.
  • Review pattern-recognition questions for figural reasoning.
  • Practice with time limits so you get used to the pace of the test.
  • Follow the test administrator’s directions exactly on test day.

POSS Study Resources

Top Study Guide:

Best Online Course:

POSS and Plant Operator Selection System are used here for identification purposes only. Edison Electric Institute is not involved with or affiliated with Mometrix Media LLC, nor does Edison Electric Institute endorse or sponsor any of the products or services offered by Mometrix Media LLC.

 

Last Updated: July 21, 2026