NivaarExam PrepOfficial exam papers ↗

04-BS-10: Undated paper

Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)

  1. Question 1 Ideal Reheat Rankine Cycle, Exergy Destruction by Process
  2. Question 2 Regenerative Brayton Cycle, Exergy Destruction by Process
  3. Question 3 Two-Stage R-134a Compression Refrigeration with Flash Chamber
  4. Question 4 Ideal Air-Standard Dual Cycle
  5. Question 5 Ideal Brayton Refrigeration (Gas Refrigeration) Cycle
  6. Question 6 R-134a Refrigerator, Subcooled Condenser Exit
  7. Question 7 Rigid Insulated Tank, Paddle-Wheel Stirring
  8. Question 8 Rigid Tank, N₂/O₂ Ideal-Gas Mixture
  9. Question 9 Window Air Conditioner — Psychrometric Dehumidification

Start with Question 1 →

National Examinations — 04-BS-10, Thermodynamics. Three hours. Closed-book exam with one 8.5×11 in. double-sided sheet of notes allowed and an approved Casio or Sharp calculator; property tables and charts are supplied and interpolation is not necessary — the closest tabular value may be used. Part A: two of three 20-mark questions; Part B: four of six 15-mark questions. Every question is answered in full.

Reference texts. Cengel & Boles, Thermodynamics: An Engineering Approach, 8th ed. (Vapor Power Cycles Ch. 10; Gas Power Cycles Ch. 9; Refrigeration Cycles Ch. 11; Gas Mixtures Ch. 13; Psychrometrics Ch. 14; Exergy Ch. 8).

Check — paper format. The paper is headed "National Examination – May 2019 / 04-BS-10, Thermodynamics, 3 Hours Duration": four question pages followed by a 22-page appendix of property tables and a psychrometric chart. All nine questions are answered in full (Part A questions 1–3 at 20 marks each, Part B questions 4–9 at 15 marks each; the paper asks for two of Part A and four of Part B). Two wording notes from the printed page: Question 2's final sub-part is printed "(d) the second law efficiency" after an earlier "(d)", i.e. the paper repeats the letter, and Question 3(d) is printed "in kJ/K" for a quantity that is a rate of exergy destruction in kJ/s.