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FE · 9% of the exam

Thermodynamics and Heat Transfer practice questions

10 free Thermodynamics and Heat Transfer questions for the FE Other Disciplines Exam (FE) exam, each with the correct answer and an explanation for every option.

Start the questionsFree 10-question FE quiz

What this domain covers

Energy, its conversion and its transfer: properties of substances, the laws of thermodynamics, power cycles and heat transfer modes.

Exam weight
9%
On a real exam
≈ 10 questions
In our bank
54 questions

Topics that come up most

  • Ideal gas law and property tables
  • First law for closed and open systems
  • Second law, entropy and cycle efficiency
  • Conduction and thermal resistance
  • Convection and radiation

How to study it

Practise finding states in the steam tables in the Handbook, including interpolation and quality; cycle questions depend on reading them correctly.

Sample Thermodynamics and Heat Transfer questions

Try each one before opening the answer. Original questions written to the official exam objectives.

  1. Question 1

    A Carnot heat pump operates between a cold reservoir at 250 K and a warm space at 300 K. Its heating coefficient of performance is closest to:

    • A0.17
    • B5
    • C1.2
    • D6
    Show answer and explanation

    Answer: D) 6

    The Carnot heating COP is T_H/(T_H − T_C) = 300/50 = 6. This equals the refrigeration COP (5) plus 1.

    • AIncorrect. (T_H − T_C)/T_H = 50/300 ≈ 0.17 is the Carnot heat-engine efficiency, which is the reciprocal of the heat-pump COP.
    • BIncorrect. T_C/(T_H − T_C) = 250/50 = 5 is the Carnot refrigeration COP, not the heating COP.
    • CIncorrect. 300/250 = 1.2 is just the temperature ratio and is not a COP expression.
    • DCorrect. COP_HP = T_H/(T_H − T_C) = 300/(300 − 250) = 6.

  2. Question 2

    How much heat raises 2 kg of water by 10 °C, using c = 4.18 kJ/(kg·K)?

    • A41.8 kJ
    • B83.6 kJ
    • C8.36 kJ
    • D836 kJ
    Show answer and explanation

    Answer: B) 83.6 kJ

    • AIncorrect. Use the 2-kg mass.
    • BCorrect. Q = mcΔT = 2(4.18)(10).
    • CIncorrect. Multiply by the 10-K rise.
    • DIncorrect. Recheck the arithmetic.

  3. Question 3

    If a radiating surface's absolute temperature doubles, its emitted radiant power changes by a factor of:

    • A4
    • B2
    • C16
    • D8
    Show answer and explanation

    Answer: C) 16

    • AIncorrect. That's T², not T⁴.
    • BIncorrect. Radiation varies with T⁴.
    • CCorrect. Stefan–Boltzmann: q ∝ T⁴, and 2⁴ = 16.
    • DIncorrect. That's T³, not T⁴.

  4. Question 4

    An ideal gas at 100 kPa and 2 m³ is compressed at constant temperature to 0.5 m³. Its final pressure is:

    • A100 kPa
    • B25 kPa
    • C200 kPa
    • D400 kPa
    Show answer and explanation

    Answer: D) 400 kPa

    • AIncorrect. Pressure changes with volume.
    • BIncorrect. Compression raises pressure.
    • CIncorrect. The volume ratio is 4.
    • DCorrect. Boyle's law: P₂ = P₁V₁/V₂.

  5. Question 5

    Steam at a given pressure is described as superheated when its temperature is:

    • AEqual to the saturation temperature at its pressure, with quality between 0 and 1
    • BBelow the saturation temperature at its pressure
    • CAbove the saturation temperature at its pressure
    • DEqual to the saturation temperature at its pressure, with quality of 1.0
    Show answer and explanation

    Answer: C) Above the saturation temperature at its pressure

    Steam is superheated when its temperature is above the saturation temperature for its pressure. At exactly T_sat with x = 1 it is saturated vapor, and below T_sat it is compressed liquid.

    • AIncorrect. This describes a saturated liquid–vapor mixture, where liquid and vapor exist together at T_sat.
    • BIncorrect. Water below T_sat at its pressure is a compressed (subcooled) liquid.
    • CCorrect. Vapor heated above T_sat for its pressure is superheated. No liquid is present, and temperature and pressure are independent properties.
    • DIncorrect. Quality 1.0 at T_sat is saturated vapor. Any further heat added at that pressure would superheat it.

  6. Question 6

    A 2-m² surface is 30 K hotter than the surrounding air. The convection heat transfer coefficient is h = 15 W/(m²·K). The rate of convection heat loss from the surface is most nearly:

    • A900 W
    • B450 W
    • C225 W
    • D1,800 W
    Show answer and explanation

    Answer: A) 900 W

    Convection heat transfer follows Newton's law of cooling, q = hAΔT. Here that gives 15 × 2 × 30 = 900 W.

    • ACorrect. Newton's law of cooling: q = hAΔT = 15 × 2 × 30 = 900 W.
    • BIncorrect. This uses an area of 1 m² instead of 2 m² (15 × 30 = 450 W).
    • CIncorrect. This divides by the area instead of multiplying (15 × 30 / 2 = 225 W).
    • DIncorrect. This counts the area twice (15 × 2 × 2 × 30 = 1,800 W). The surface area is used only once in q = hAΔT.

  7. Question 7

    A slab (k = 50 W/m·K) is 0.1 m thick with an area of 0.5 m² and a 40 K temperature difference. The conduction heat rate is:

    • A1,000 W
    • B100 W, multiplying by thickness
    • C10,000 W
    • D20,000 W
    Show answer and explanation

    Answer: C) 10,000 W

    • AIncorrect. That's off by a factor of 10.
    • BIncorrect. Divide by thickness.
    • CCorrect. \(q = kA\Delta T/L\).
    • DIncorrect. That uses 1 m².

  8. Question 8

    A blackbody surface is at 400 K. Using σ = 5.67 × 10⁻⁸ W/(m²·K⁴), its emissive power is most nearly:

    • A1,452 W/m²
    • B3.6 W/m²
    • C5,806 W/m²
    • D145 W/m²
    Show answer and explanation

    Answer: A) 1,452 W/m²

    Blackbody emissive power follows the Stefan-Boltzmann law, Eb = σT⁴, with T in kelvin. At 400 K this is about 1,452 W/m².

    • ACorrect. Eb = σT⁴ = 5.67 × 10⁻⁸ × (400)⁴ = 5.67 × 10⁻⁸ × 2.56 × 10¹⁰ ≈ 1,452 W/m².
    • BIncorrect. This uses temperature to the third power (σT³ = 5.67 × 10⁻⁸ × 6.4 × 10⁷ ≈ 3.6). The Stefan-Boltzmann law uses T⁴.
    • CIncorrect. This is 4σT⁴, four times the correct value. The Stefan-Boltzmann law has no factor of 4. (The 4 shows up in the derivative 4σT³, which is used for linearized radiation coefficients, and that is a different quantity.)
    • DIncorrect. This is too small by a factor of 10, usually because of a power-of-ten mistake in σ or in 400⁴ (2.56 × 10¹⁰).

  9. Question 9

    A heat engine takes in 100 kJ of heat and produces 40 kJ of net work. Its thermal efficiency is:

    • A60%
    • B40%
    • C250%
    • D140%
    Show answer and explanation

    Answer: B) 40%

    • AIncorrect. That's the share rejected as heat.
    • BCorrect. η = W/Q_H = 40/100.
    • CIncorrect. That's inverted.
    • DIncorrect. Efficiency can't exceed 100%.

  10. Question 10

    A gas temperature of 27 °C, expressed on the absolute Kelvin scale for ideal-gas calculations, is about:

    • A300 K
    • B246 K
    • C27 K
    • D81 K
    Show answer and explanation

    Answer: A) 300 K

    • ACorrect. K = °C + 273.
    • BIncorrect. Add 273; don't subtract.
    • CIncorrect. Convert to the absolute scale.
    • DIncorrect. Add 273 to the Celsius value.

Thermodynamics and Heat Transfer: FAQs

How much of the FE exam is Thermodynamics and Heat Transfer?

Thermodynamics and Heat Transfer is 9% of the FE exam by the official exam guide's weighting, which on a 110-question form works out to roughly 10 questions. The real exam's exact split varies by form.

What does the Thermodynamics and Heat Transfer domain cover?

Energy, its conversion and its transfer: properties of substances, the laws of thermodynamics, power cycles and heat transfer modes.

How should I study Thermodynamics and Heat Transfer for FE?

Practise finding states in the steam tables in the Handbook, including interpolation and quality; cycle questions depend on reading them correctly.

Where can I practise more Thermodynamics and Heat Transfer questions?

This page has 10 free Thermodynamics and Heat Transfer questions with answers. The ExamWize FE question bank has 54 questions in this domain. Every practice exam result breaks your score down by domain, and Review Mode re-drills the questions you missed.

Other FE topics

Also: 15 free questions across all topics, the FE cheat sheet and the study guide.

Get Thermodynamics and Heat Transfer exam-ready

The full FE bank has 54 Thermodynamics and Heat Transfer questions. Timed practice exams match the real exam's length and domain weights, every result shows your score per domain, and Review Mode re-drills the questions you missed.

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Not affiliated with NCEES; questions are original, written from the official exam outline, and never copied from the real exam.