MASS Practice Test

Prepare for your test with realistic questions.

The Power Plant Maintenance Positions Selection System (MASS) test is an exam designed by the Edison Energy Institute (EEI) to assess your aptitude and skills in relation to power plant maintenance positions, such as those in fossil, hydroelectric, or nuclear power plants.

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MASS Exam Outline

The MASS is a multiple-choice, paper-and-pencil aptitude test containing 118 multiple-choice questions. You will be given about hours to complete the test, with times varying slightly across companies.

The exam is split into four test batteries:

1. Reading Comprehension (36 questions)

In this battery, you will be given 30 minutes to read five short passages based on technical concepts. For each passage, you will need to answer several related questions before moving on to the next passage.

2. Mechanical Concepts (44 questions)

In this battery, which is timed at 20 minutes, you will be given pictorial descriptions of various mechanical situations and must answer at least one question per situation given.

3. Assembling Objects (20 questions)

In this battery, which has a 15-minute time limit, there are two types of questions. The first type provides you with a diagram of labeled parts, and you must correctly assemble the parts by matching the letters. The second type provides you with a diagram of unlabeled parts and four possible assemblances of those parts, and you must correctly identify which assemblance is correct.

4. Mathematical Usage (18 questions)

In this battery, you will be given 7 minutes to solve basic mathematical problems.

exam outline for the MASS test, which contains 118 multiple-choice questions and has a time limit of about 2 hours

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How the MASS Exam is Scored

Your score is determined by the number of questions you answer correctly. This means there is no penalty for answering a question incorrectly, so you should at least pencil in a guess if you aren’t sure of the correct answer.

Your scores for each section of the test are combined into an index score on a range of 0-15. The score needed to pass the exam will be different depending on the job you wish to pursue and at which company you wish to work.

How to Study for the MASS Exam

How to Study Effectively

Your success on MASS test day depends not only on how many hours you put into preparing but also on whether you prepared the right way. It’s good to check along the way to see whether your studying is paying off. One of the most effective ways to do this is by taking MASS practice tests to evaluate your progress. Practice tests are useful because they show exactly where you need to improve. Every time you take a free MASS exam practice test, pay special attention to these three groups of questions:

  • The questions you got wrong
  • The ones you had to guess on, even if you guessed right
  • The ones you found difficult or slow to work through

This will show you exactly what your weak areas are and where you need to devote more study time. Ask yourself why each of these questions gave you trouble. Was it because you didn’t understand the material? Was it because you didn’t remember the vocabulary? Do you need more repetitions on this type of question to build speed and confidence? Dig into those questions and figure out how you can strengthen your weak areas as you go back to review the material.

Answer Explanations

Additionally, many MASS practice tests have a section explaining the answer choices. It can be tempting to read the explanation and think that you now have a good understanding of the concept. However, an explanation likely only covers part of the question’s broader context. Even if the explanation makes sense, go back and investigate every concept related to the question until you’re positive you have a thorough understanding.

Comprehend Each Topic

As you go along, keep in mind that the MASS practice test is just that: practice. Memorizing these questions and answers will not be very helpful on the actual test because it is unlikely to have any of the same exact questions. If you only know the right answers to the sample questions, you won’t be prepared for the real thing. Study the concepts until you understand them fully, and then you’ll be able to answer any question that shows up on the test.

Strategy for MASS Practice

When you’re ready to start taking practice tests, follow this strategy:

  • Remove Limitations. Take the first test with no time constraints and with your notes and MASS study guide handy. Take your time and focus on applying the strategies you’ve learned.
  • Time Yourself. Take the second practice test “open book” as well, but set a timer and practice pacing yourself to finish in time.
  • Simulate Test Day. Take any other practice tests as if it were test day. Set a timer and put away your study materials. Sit at a table or desk in a quiet room, imagine yourself at the testing center, and answer questions as quickly and accurately as possible.
  • Keep Practicing. Keep taking practice tests on a regular basis until you run out of practice tests or it’s time for the actual test. Your mind will be ready for the schedule and stress of test day, and you’ll be able to focus on recalling the material you’ve learned.



How many questions are on the MASS test?


There are 118 multiple-choice questions on the test.


How long is the MASS test?


The time limit for this test varies, but is generally about 2 hours.


What is the passing score for the MASS test?


There is no set passing score for this test.

By Peter Rench

Peter Rench joined Mometrix in 2009 and serves as Vice President of Product Development, responsible for overseeing all new product development and quality improvements. Mr. Rench, a National Merit Scholar, graduated magna cum laude with a Bachelor of Science in Mechanical Engineering and a minor in mathematics from Texas A&M University.


by Mometrix Test Preparation | This Page Last Updated: December 19, 2023