Free FE Environmental Practice Questions

Sample Practice Questions

Try these 10 sample questions from the FE Environmental practice bank. Each includes the answer and explanation. Continue with the interactive practice above to review the full question set.

1. 1A straight line passes through (2, 5) and (8, 17). What is its slope?

   1. A. 0.5
   2. B. 2.0
   3. C. 2.5
   4. D. 6.0

   Answer: B

   Explanation: The handbook states, "For a straight line, slope is equal to rise over run". Thus m = (17 − 5)/(8 − 2) = 2.0. Reversing rise and run gives 0.5; using a point's coordinate ratio gives 2.5.

   Reference: DOE Fundamentals Handbook: Mathematics, Volume 1 of 2 — Module 2, Slopes, p. 85

2. 2An engineer experienced in water treatment is asked to take sole technical responsibility for an unfamiliar structural design. The engineer lacks relevant structural education and experience. Under the NSPE Code, which response satisfies the competence requirement?

   1. A. Accept because the work is within the engineering profession
   2. B. Accept because the client has agreed to the engineer's involvement
   3. C. Decline sole responsibility until appropriately qualified for that work
   4. D. Accept because a professional liability policy covers design work

   Answer: C

   Explanation: NSPE restricts services to "areas of their competence". Relevant education or experience is required for the specific technical field. General engineering status, client consent, and insurance do not establish structural competence.

   Reference: NSPE Code of Ethics for Engineers — II.2 and II.2.a, competence

3. 3A project's present capital cost is $100,000. Its five-year capital recovery factor at the specified interest rate is 0.2638. What is the equivalent uniform annual capital cost?

   1. A. $20,000
   2. B. $26,380
   3. C. $73,620
   4. D. $379,075

   Answer: B

   Explanation: EIA defines the capital recovery factor as one that "converts a net present value into an annuity value". The annual cost is $100,000 × 0.2638 = $26,380. Dividing by the factor reverses the conversion; dividing by five ignores interest.

   Reference: EIA Engineering Economic Analysis Guide: Liquid Fuels Technologies — Appendix A, Capital recovery factor, p. 27

4. 4For a dilute aqueous solution with hydrogen-ion concentration 1.0 × 10⁻⁵ mol/L, what is the concentration-based pH?

   1. A. 5
   2. B. 9
   3. C. 0.00001
   4. D. 100000

   Answer: A

   Explanation: DOE states, "The formula for pH is: pH = -log [H+]". Using base-10 logarithms gives −log₁₀(10⁻⁵) = 5. The value 9 confuses pH with pOH at 25°C; 0.00001 is the concentration itself, and 100000 is its reciprocal without taking the logarithm.

   Reference: DOE Fundamentals Handbook: Chemistry, Volume 1 of 2 — Module 1, Acids, Bases, Salts, and pH Summary, p. 53

5. 5A noncancer assessment uses a NOAEL of 10 mg/kg/day and two uncertainty factors of 10 each, with no other adjustments. What reference dose results?

   1. A. 1.0 mg/kg/day
   2. B. 0.5 mg/kg/day
   3. C. 0.1 mg/kg/day
   4. D. 0.01 mg/kg/day

   Answer: C

   Explanation: EPA gives "RfD = NOAEL (or LOAEL or BMDL) / UFs" and states that uncertainty factors are multiplied. The combined factor is 10 × 10 = 100, so RfD = 10/100 = 0.1 mg/kg/day. Adding the two factors would incorrectly give 0.5.

   Reference: EPA: Conducting a Human Health Risk Assessment — Step 2, Non-linear dose-response assessment, RfD equation

6. 6A closed system receives 500 kJ of heat and does 200 kJ of work on its surroundings. Kinetic and potential energy changes are negligible. What is its internal-energy change?

   1. A. −200 kJ
   2. B. +500 kJ
   3. C. +700 kJ
   4. D. +300 kJ

   Answer: D

   Explanation: DOE states that energy entering equals energy leaving "plus the change in storage of energies within the system." Thus ΔU = Qin − Wout = 500 − 200 = +300 kJ.

   Reference: DOE Fundamentals Handbook: Thermodynamics, Heat Transfer, and Fluid Flow, Volume 1 of 3 — Module 1, First Law of Thermodynamics, p. 54

7. 7For a small catchment under applicable Rational Method assumptions, rainfall intensity is 36 mm/h over 10 hectares and the runoff coefficient is 0.50. What peak runoff rate results?

   1. A. 0.05 m³/s
   2. B. 0.50 m³/s
   3. C. 1.00 m³/s
   4. D. 5.00 m³/s

   Answer: B

   Explanation: FHWA defines C as "the ratio of the rate of runoff to the rate of rainfall". Rainfall input is 0.036 m/h × 100,000 m² = 3,600 m³/h. Multiplying by 0.50 and dividing by 3,600 s/h gives 0.50 m³/s.

   Reference: FHWA: Introduction to Highway Hydraulics, Metric Version — 2.5.2, Runoff Coefficient

8. 8Which water-quality measurement primarily characterizes the scattering and absorption of light by suspended matter?

   1. A. Alkalinity
   2. B. Turbidity
   3. C. Total hardness
   4. D. Specific conductance

   Answer: B

   Explanation: The USACE manual states, "Turbidity results from optical properties that cause light to be scattered and/or absorbed rather than transmitted directly through the medium of interest." Thus turbidity characterizes the optical effect of suspended matter; alkalinity, hardness, and conductance characterize different chemical properties.

   Reference: USACE: Design of Small Water Systems — Page 3-11, Contaminants Found in Water Supplies, Turbidity—Definition

9. 9What is the distinction between primary and secondary National Ambient Air Quality Standards?

   1. A. Primary standards protect workers; secondary standards protect nearby residents
   2. B. Primary standards address gases; secondary standards address particles
   3. C. Primary standards apply to indoor air; secondary standards apply outdoors
   4. D. Primary standards protect public health; secondary standards protect public welfare

   Answer: D

   Explanation: EPA states, "Primary standards provide public health protection" and "Secondary standards provide public welfare protection". Welfare protection includes visibility and effects on crops, animals, vegetation, and buildings. The distinction is not worker versus resident, gas versus particle, or indoor versus outdoor.

   Reference: NAAQS Table — NAAQS Table, introductory explanation of standards

10. 10Which process occurs in a photovoltaic cell when it generates electricity?

    1. A. Sunlight heats a working fluid that drives a steam turbine
    2. B. Sunlight directly creates electrical output in semiconductor material
    3. C. A temperature difference drives a thermoelectric generator
    4. D. Solar heat releases fuel that is burned in a gas turbine

    Answer: B

    Explanation: EIA states, "A photovoltaic (PV) cell, commonly called a solar cell, is a nonmechanical device that converts sunlight directly into electricity." The photovoltaic effect differs from solar-thermal power cycles, thermoelectric conversion, and fuel combustion.

    Reference: Solar Photovoltaics and Electricity — Photovoltaic cells