Free Thermodynamics MCQs with Answers
714 Thermodynamics MCQs from Physics, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Thermal equilibrium and heat explain how temperature and energy transfer are related, while molar specific heats describe the heat required by a gas at constant volume or constant pressure. The first law connects heat supplied, work done and change in internal energy, with sign conventions kept distinct from temperature changes.
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Read the Thermodynamics notesFree MDCAT chapter notes with key terms714 questions · page 21 of 36
- A. Increases
- B. Decreases
- C. Remains constant
- D. Becomes zero
Explanation: In a reversible adiabatic process, no heat is exchanged (Q = 0), so the entropy change (ΔS = Q/T) is zero, and the system's entropy…
Correct answer: Remains constant- A. 4520 kJ
- B. 9040 kJ
- C. 2260 kJ
- D. 4180 kJ
Explanation: For the phase change from water to steam at 100°C, only latent heat is required (no temperature change). Heat = m·Lv = 2 × 2260 = 4520 kJ.
Correct answer: 4520 kJ- A. A downward sloping curve
- B. A straight vertical line
- C. An upward sloping curve
- D. A hyperbolic curve
Explanation: PV=nRT, where nRT are constants in isothermal process (no temperature change) so graph D is the valid answer.
Correct answer: A hyperbolic curve- A. Adiabatic
- B. Isobaric
- C. Isochoric
- D. Isothermal
Explanation: Isochoric :In isochoric process the volume remain same and the pressure increase with rise in temperature and the graph of isochoric…
Correct answer: Isochoric405. Maxwell's velocity distribution curve is given for two different temperature. For the given curves:
- A. T1 > T2
- B. T1 < T2
- C. T1 ≤ T2
- D. T1 = T2
Explanation: Higher is the temperature greater is the most probable velocity. Hence, this option is correct.
Correct answer: T1 < T2- A. Temperature difference
- B. Pressure difference
- C. Volume change
- D. Entropy change
Explanation: According to Fourier's law, heat transfer by conduction is proportional to the temperature difference across the material, driving the…
Correct answer: Temperature difference- A. Gases
- B. Liquids
- C. Metals
- D. Insulators
Explanation: Metals have high thermal conductivity due to free electrons that efficiently transfer heat, unlike gases, liquids, or insulators, which…
Correct answer: Metals- A. 334 J/K
- B. 1226 J/K
- C. 273 J/K
- D. 1000 J/K
Explanation: Entropy change for a phase transition is ΔS = ΔH/T, where ΔH = 334 kJ/kg = 334,000 J/kg and T = 0°C = 273 K.
Correct answer: 1226 J/K- A. 84,000 J
- B. -2000/4.2 J
- C. 2000/4.2 J
- D. -8400
Explanation: To calculate the heat absorbed by a substance, we can use the formula:q = m * C * ΔTWhere:q is the heat absorbed or released,m is the mass…
Correct answer: -8400- A. Δ𝛉 + 373
- B. Δ𝛉 + 273
- C. Δ𝛉 + 100
- D. Δ𝛉
- E. Δ𝛉 + 212
Explanation: The change in temperature in the kelvin and Celsius scale is the same hence the answer will be D.
Correct answer: Δ𝛉- A. 1/100
- B. 1/212
- C. 1/273.16
- D. 1/32
- E. 1/98
Explanation: The correct answer is that the Kelvin is defined as 1/273.16 of the thermodynamic temperature of the triple point of water.
Correct answer: 1/273.16- A. 537.1 x 10^-5 m
- B. 447.5 x 10^-5 m
- C. 327.5 x 10^-5 m
- D. 247.5 x 10^-5 m
- E. 127.5 x 10^-5 m
Explanation: The increase in length of the steel rod is calculated using the linear expansion formula: ΔL=L0⋅α⋅ΔT, where L0 is the initial length, α is…
Correct answer: 247.5 x 10^-5 m- A. Electric field
- B. Thermal expansion
- C. Heat engine
- D. Isobaric process
Explanation: Bimetal Thermostats use two different kinds of metal to regulate the temperature setting.
Correct answer: Thermal expansion- A. Decreasing the applied pressure
- B. Increasing the applied pressure
- C. Increasing the applied pressure with double force
- D. Increasing the weight
Explanation: Boyle's law: states that the volume of a given amount of gas held at constant temperature varies inversely with the applied pressure when…
Correct answer: Decreasing the applied pressure- A. 22.22%
- B. 23.23%
- C. 25.25%
- D. 30.30%
Explanation: The efficiency of the Carnot engine working between 177°C and 77°C will be 22.22%.Right answer is A.Explanation:T1=177°C + 273=450…
Correct answer: 22.22%- A. 1/100.6
- B. 1/273.16
- C. 1/32.6
- D. 1/241.6
- E. 1/115.7
Explanation: The Kelvin scale is defined by the International System of Units (SI) such that one Kelvin is exactly 1/273.16 of the thermodynamic…
Correct answer: 1/273.16- A. 8 g and 100 degrees centigrade
- B. 100 g and 90 degrees centigrade
- C. 92 g and 100 degrees centigrade
- D. 82g and 100 degrees centigrade
Explanation: Given, heat supplied = 22320 calmass of ice = 100glatent heat of fusion of ice = 80 cal/glatent heat of vaporization of water = 540…
Correct answer: 92 g and 100 degrees centigrade- A. Gets negligible
- B. Gets constant
- C. Rises
- D. Falls
Explanation: Gay-Lussac's Law. This law states that the pressure of a given amount of gas held at constant volume is directly proportional to the…
Correct answer: Rises- A. P = ⅓ Nm/v2 (c2)
- B. P = ⅓ Nm/v2 (c)
- C. P = ⅓ Nm/v (c2)
- D. P = ⅕ Nm2 / v (c2)
- E. P = ⅓ N2m2/v (c2)
Explanation: The dimensions of pressure can be expressed as force per unit area, or [M L-1 T-2].Using the method of dimensions, we can check which…
Correct answer: P = ⅓ Nm/v (c2)- A. 327 K
- B. 177 C
- C. 873 K
- D. 600 oC
Explanation: Option A: 327 K. This is the temperature if the volume of the gas doubles.
Correct answer: 177 C