# Free PE Power Practice Exam Problems

The Principles and Practice of Engineering (PE) Power exam is the final step in becoming a licensed professional engineer. The PE power exam consists of 80 questions, which will be difficult to answer if you aren’t familiar with the type of questions likely to be appearing in the exam.

We have covered some Power practice exam problems and their solutions in this article to take you out of this difficulty. Solving the PE Power practice questions will help you grasp the concepts and give you an idea about where you stand, ultimately leading you to better prepare for the PE Power exam.

Not to forget, the PE power exam is eight-hour-long, so time management is the key as you will only have six minutes to solve each problem. Solving PE Power Practice Exam Problems helps you get an idea about how much time each question will take, enabling you to answer the maximum number of questions in the minimum amount of time in the exam.

### Sample Practice Problems For PE Power Exam

#### Problem #1

#### Use ‘Schlumberger Method’ to calculate ground resistance in an area where soil resistivity is known to be 100Ω.m. Distance between the outermost electrodes of ‘Schlumberger Array’ is 20m and the distance between the inner electrodes is 4m.

#### Use ‘Schlumberger Method’ to calculate ground resistance in an area where soil resistivity is known to be 100Ω.m. Distance between the outermost electrodes of ‘Schlumberger Array’ is 20m and the distance between the inner electrodes is 4m.

#### Problem #2

#### The lobby of a hotel is 200ft (W)×100ft (L)×30 ft (H). Target illumination level for the lobby is 50fc. The selected luminaire for this application has 8 lamps and each lamp has an output of 750 lumens. The luminaires will be mounted at a height of 25 ft from the floor and working plane will be 3 ft from the floor. Lamp lumen depreciation factor is 0.90, luminaire dirt depreciation factor is 0.85, coefficient of utilization is 0.80, wall luminance coefficient is 0.25, ceiling cavity luminance coefficient is 0.30 and room position multiplier is 0.75. The minimum number of luminaires that will be required for this application are _____.

#### The lobby of a hotel is 200ft (W)×100ft (L)×30 ft (H). Target illumination level for the lobby is 50fc. The selected luminaire for this application has 8 lamps and each lamp has an output of 750 lumens. The luminaires will be mounted at a height of 25 ft from the floor and working plane will be 3 ft from the floor. Lamp lumen depreciation factor is 0.90, luminaire dirt depreciation factor is 0.85, coefficient of utilization is 0.80, wall luminance coefficient is 0.25, ceiling cavity luminance coefficient is 0.30 and room position multiplier is 0.75. The minimum number of luminaires that will be required for this application are _____.

#### Problem #3

#### Calculate the maximum rating of a non-time-delay fuse for overcurrent protection of a feeder supplying a group of four 3-phase, 575V, synchronous-type unity power factor motors with following horsepower ratings (assume 75⁰C rated terminals) as per NEC® 2017. These motors will be protected by a dedicated branch-circuit overcurrent protection device in the form of a non-time-delay fuse. MotorA= 25 hp, MotorB= 30 hp, MotorC= 40 hp, MotorD= 50 hp.

#### Calculate the maximum rating of a non-time-delay fuse for overcurrent protection of a feeder supplying a group of four 3-phase, 575V, synchronous-type unity power factor motors with following horsepower ratings (assume 75⁰C rated terminals) as per NEC® 2017. These motors will be protected by a dedicated branch-circuit overcurrent protection device in the form of a non-time-delay fuse. MotorA= 25 hp, MotorB= 30 hp, MotorC= 40 hp, MotorD= 50 hp.

#### Problem #4

#### A 3-phase, 15kV/5kV, 𝛥-Y, 60Hz, 10MVA power distribution transformer has 5% per-unit leakage reactance and negligible resistance. The actual transformer impedance based on the ratings on its high voltage side is ____.

#### A 3-phase, 15kV/5kV, 𝛥-Y, 60Hz, 10MVA power distribution transformer has 5% per-unit leakage reactance and negligible resistance. The actual transformer impedance based on the ratings on its high voltage side is ____.

#### Problem #5

#### A three-phase 2MVA 13.8kV/480V oil-filled service entrance transformer is fed by a local electrical utility which can be assumed as an infinite bus. Transformer impedance is Z = 5%. Calculate symmetrical fault current due to three-phase short circuit at transformer’s secondary windings.

#### A three-phase 2MVA 13.8kV/480V oil-filled service entrance transformer is fed by a local electrical utility which can be assumed as an infinite bus. Transformer impedance is Z = 5%. Calculate symmetrical fault current due to three-phase short circuit at transformer’s secondary windings.

### Frequently Asked Questions

The PE Power practice exam comprises questions similar to those on the actual exam, so working through PE practice problems will help you approach each question with logical thinking.

The PE power practice exam allows you to practice taking the Principles and Practice of Engineering (PE) examination. It is believed that this experience will make you more comfortable and prepared on the day of the exam.

Moreover, PE Power practice exams can help you assess your knowledge and knowledge gaps. It mirrors the structure, style, and complexity, includes prior exam problems, and offers solutions or performance evaluations for each subject area.

Studying for the PE Power exam must include getting familiar with the relevant equations, solutions, and critical details. You can only accomplish this if you practice a lot. So, set a target to answer a particular number of **PE exam sample questions** daily.

Studying for the PE Power exam must include getting familiar with the relevant equations, solutions, and critical details. You can only accomplish this if you practice a lot. So, set a target to answer a particular number of **PE exam sample questions** daily.

There is no specific passing score for the PE Power exam that NCEES® has established. However, the average passing percentage for the PE Power exam is estimated to be around 70%.

It implies that you must correctly respond to nearly 70% of the questions, that is approximately 56 out of 80 correct answers. Remember that this pass rate is based only on the student’s experiences and is not always accurate.

Although it can vary for each person as each student has a different skill level, ideally, you should start preparing for the PE power exam four months before the test date, averaging up to 200-300 hours.

You should dedicate at least two to four hours a day and five days a week. The least you can start studying is three months before the PE power exam, which will take approximately 150-200 hours. For example, your PE power exam is due in June. In that case, you should begin preparing for it in March.