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Energy ExamSprint Handbook
Question 1. Which of the following best defines a conservative pollutant in environmental engineering? A) Degrades biologically over time B) Undergoes photolysis in the atmosphere C) Remains chemically unchanged during transport D) Reacts with suspended solids Answer: C Explanation: Conservative pollutants do not undergo chemical or biological transformation while moving through the environment. Question 2. In a steady-state mass balance for a continuous stirred-tank reactor (CSTR), which term is zero? A) Inflow rate B) Outflow rate C) Accumulation term D) Reaction rate Answer: C Explanation: At steady state, accumulation (change in mass with time) equals zero. Question 3. The stoichiometric oxygen demand for complete combustion of methane (CH₄) is: A) 2 g O₂/g CH₄ B) 4 g O₂/g CH₄ C) 1 g O₂/g CH₄
Energy ExamSprint Handbook
D) 0.5 g O₂/g CH₄ Answer: B Explanation: CH₄ + 2O₂ → CO₂ + 2H₂O; thus 2 mol O₂ (64 g) per 16 g CH₄ = 4 g O₂/g CH₄. Question 4. The dose-response relationship used in risk assessment is typically: A) Linear at low doses B) Exponential for all doses C) Sigmoidal with a threshold D) Independent of dose Answer: A Explanation: For many carcinogens, a linear no-threshold model is assumed at low exposure levels. Question 5. The Lifetime Average Daily Dose (LADD) is calculated by dividing the total absorbed dose by: A) Body weight only B) Exposure duration only C) The product of exposure duration and body weight D) The averaging time (in days) Answer: D Explanation: LADD = (Σ dose × exposure time) / averaging time, usually lifetime in days.
Energy ExamSprint Handbook
D) Adjust pH Answer: C Explanation: Coagulants neutralize surface charges, allowing colloids to aggregate into larger flocs. Question 9. In a typical activated-sludge system, the mixed liquor suspended solids (MLSS) concentration is usually: A) 10–30 mg/L B) 100–500 mg/L C) 1,000–3,000 mg/L D) 5,000–10,000 mg/L Answer: C Explanation: Conventional activated sludge operates with MLSS in the range of 1,000–3,000 mg/L. Question 10. The primary electron acceptor for anaerobic digestion is: A) Nitrate B) Sulfate C) Carbon dioxide D) Oxygen Answer: C Explanation: In methanogenesis, CO₂ is reduced to CH₄, serving as the electron acceptor.
Energy ExamSprint Handbook
Question 11. The atmospheric lapse rate that characterizes a stable atmosphere is: A) Greater than the dry adiabatic lapse rate B) Equal to the moist adiabatic lapse rate C) Less than the dry adiabatic lapse rate D) Zero Answer: C Explanation: A stable atmosphere cools more slowly with height than the dry adiabatic rate. Question 12. In Gaussian plume modeling, the term σ_y represents: A) Horizontal spread due to turbulence B) Vertical spread due to buoyancy C) Wind speed at stack height D) Stack exit velocity Answer: A Explanation: σ_y is the standard deviation of concentration in the cross-wind direction. Question 13. Which pollutant is NOT classified as a criteria pollutant by the EPA? A) Ozone (O₃) B) Lead (Pb) C) Carbon monoxide (CO)
Energy ExamSprint Handbook
A) Sodium hydroxide B) Calcium carbonate C) Limestone slurry (CaCO₃) D) Sodium chloride Answer: C Explanation: Limestone slurry reacts with SO₂ to form gypsum (CaSO₄·2H₂O). **Question 17. The hierarchy of waste management places “recycle” at which rank? ** A) First B) Second C) Third D) Fourth Answer: C Explanation: The hierarchy is Reduce → Reuse → Recycle → Recover → Dispose. Question 18. A typical composite liner for a sanitary landfill consists of: A) Two layers of compacted clay only B) A geomembrane over a compacted clay layer C) A geosynthetic clay liner alone D) No liner; reliance on natural soil Answer: B
Energy ExamSprint Handbook
Explanation: Composite liners combine a low-permeability geomembrane with a compacted clay to enhance barrier performance. Question 19. The RCRA regulation that governs hazardous waste generators is found in: A) Subpart C B) Subpart D C) Subpart B D) Subpart A Answer: C Explanation: Subpart B of RCRA defines generator categories (small, large, universal). Question 20. Bioremediation of a petroleum-contaminated site most commonly relies on which process? A) Phytovolatilization B) Aerobic microbial degradation C) Thermal desorption D) Chemical oxidation Answer: B Explanation: Aerobic microbes metabolize hydrocarbons to CO₂ and water. Question 21. The Carnot efficiency for a power plant operating between 600 K (source) and 300 K (sink) is: A) 25%
Energy ExamSprint Handbook
Answer: D Explanation: Betz’s law gives a theoretical maximum efficiency of 59.3%. Question 24. Concentrated Solar Power (CSP) systems differ from photovoltaics primarily because CSP: A) Generates electricity directly from photons B) Uses mirrors to produce high-temperature heat C) Operates only at night D) Requires semiconductor materials Answer: B Explanation: CSP concentrates sunlight to produce thermal energy for a heat engine. Question 25. The primary environmental concern associated with geothermal energy extraction is: A) Emission of CO₂ from combustion B) Depletion of fossil fuel reserves C) Release of dissolved gases such as H₂S D) Large land-use footprint Answer: C Explanation: Geothermal fluids can contain hydrogen sulfide and other gases that may be released. Question 26. The most widely used fuel in nuclear power plants is:
Energy ExamSprint Handbook
A) Plutonium- 239 B) Uranium- 235 C) Thorium- 232 D) Depleted uranium Answer: B Explanation: Enriched uranium-235 undergoes fission to produce heat in reactors. Question 27. Global warming potential (GWP) of methane over a 100-year horizon is approximately: A) 1 B) 25 C) 100 D) 300 Answer: B Explanation: Methane’s GWP ≈ 28–34; rounded to 25 in many textbooks. Question 28. The Montreal Protocol primarily addressed the phase-out of which class of compounds? A) Hydrofluorocarbons (HFCs) B) Chlorofluorocarbons (CFCs) C) Perfluorocarbons (PFCs) D) Sulfur hexafluoride (SF₆)
Energy ExamSprint Handbook
A. Chlorofluorocarbon (CFC) B. Sodium chloride (NaCl) C. Benzene (under aerobic conditions) D. Helium Answer: C Explanation: Benzene is biodegradable under aerobic conditions, thus non-conservative. Question 32. The pH of a natural water body is most directly controlled by: A. Alkalinity B. Conductivity C. Turbidity D. Total suspended solids Answer: A Explanation: Alkalinity buffers pH by neutralizing added acids or bases. Question 33. In a first-order decay reaction, the concentration after time t is given by: A. C = C₀ e^(+kt) B. C = C₀ e^(–kt) C. C = C₀ (1 – kt) D. C = C₀ /(1 + kt) Answer: B
Energy ExamSprint Handbook
Explanation: First-order kinetics follow C = C₀ e^(–kt). Question 34. The “critical velocity” in a sedimentation tank is defined as: A. The velocity at which particles begin to settle B. The maximum allowable influent velocity to avoid short-circuiting C. The velocity of the overflow weir D. The velocity of the sludge blanket Answer: B Explanation: Critical velocity is the maximum influent velocity that still allows effective particle settling. **Question 35. Which disinfectant provides a residual effect in distribution systems? ** A. Ozone B. UV radiation C. Chlorine D. Hydrogen peroxide Answer: C Explanation: Chlorine maintains a residual concentration that continues to disinfect downstream. Question 36. The term “slug flow” in wastewater treatment refers to: A. Continuous laminar flow B. Turbulent flow with bubbles
Energy ExamSprint Handbook
Question 39. The “mixing zone” downstream of a wastewater discharge point is important because: A. It reduces temperature differences B. It allows dilution of pollutants to acceptable levels C. It enhances biological oxygen demand D. It removes suspended solids Answer: B Explanation: Mixing promotes dilution, decreasing pollutant concentrations to meet regulatory limits. Question 40. In the context of air quality, the term “inversion layer” refers to: A. A region where temperature decreases with height faster than normal B. A layer where temperature increases with height, trapping pollutants C. A stable wind pattern that disperses emissions D. A region of high humidity Answer: B Explanation: Temperature inversion creates a stable layer that hinders vertical mixing of pollutants. Question 41. The main advantage of a cyclone separator over an ESP is: A. Higher collection efficiency for sub-micron particles B. No electrical power requirement C. Ability to handle corrosive gases
Energy ExamSprint Handbook
D. Lower capital cost Answer: B Explanation: Cyclones rely on inertial forces and do not need electricity. Question 42. The “acid rain” phenomenon is primarily caused by atmospheric: A. CO₂ B. SO₂ and NOₓ C. CH₄ D. O₃ Answer: B Explanation: Sulfur dioxide and nitrogen oxides oxidize to form acidic compounds that precipitate. Question 43. A landfill gas collection system typically captures which two major gases? A. CO₂ and O₂ B. CH₄ and CO₂ C. H₂S and NH₃ D. N₂ and Ar Answer: B Explanation: Decomposition produces methane and carbon dioxide, both targeted for collection.
Energy ExamSprint Handbook
D. Efficiency of the conversion process Answer: A Explanation: Capacity factor = (actual output) / (maximum possible output over the same time). Question 47. Which of the following is a major advantage of photovoltaic (PV) systems compared to CSP? A. Ability to store thermal energy easily B. Higher efficiency at high temperatures C. Direct conversion of sunlight to electricity without moving parts D. Requirement of large water resources Answer: C Explanation: PV modules convert photons directly to electricity, needing no fluids or moving components. Question 48. The term “fuel-cycle analysis” for nuclear power includes: A. Only the mining stage B. Mining, enrichment, reactor operation, and waste disposal C. Reactor operation and decommissioning only D. Renewable integration Answer: B Explanation: Fuel-cycle analysis covers all stages from extraction to final waste management.
Energy ExamSprint Handbook
Question 49. The primary greenhouse gas emitted from livestock digestion is: A. CO₂ B. CH₄ C. N₂O D. H₂O Answer: B Explanation: Enteric fermentation in ruminants produces methane. Question 50. The “global warming potential” (GWP) of a gas is measured relative to which reference gas? A. CO₂ B. CH₄ C. N₂O D. H₂O Answer: A Explanation: GWP compares the warming impact of a gas to that of carbon dioxide over a specified time horizon. Question 51. In water distribution, “head loss” due to friction is calculated using: A. Bernoulli’s equation only B. Darcy-Weisbach or Hazen-Williams formulas C. Manning’s equation D. The continuity equation
