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 23 of 36
- A. The rapid escape of air from a burst tyre
- B. The rapid expansion and compression of air through which a sound wave is passing
- C. Cloud formation in the atmosphere
- D. Slow compression or expansion of gas
Explanation: Option A: The rapid escape of air from a burst tyre: This is an example of an adiabatic process.
Correct answer: Slow compression or expansion of gas- A. Twice that of container A
- B. The same as that of container A
- C. Half that of container A
- D. Impossible to determine
Explanation: The average translational kinetic energy per molecule in an ideal gas depends only on its temperature and is given by the equation:KE_avg…
Correct answer: The same as that of container A- A. 2.01 mol
- B. 21 mol
- C. 201 mol
- D. 2001 mol
Explanation: Using the ideal gas equation PV = nRT, we can solve for n:n = PV / RTGiven:P = 1.72 x 10^5 PaV = 2.81 m^3R = 8.314 J/(mol K)T = 15.5°C =…
Correct answer: 201 mol- A. 0.25
- B. 0.75
- C. 1
- D. Impossible to determine
Explanation: Option A: States that the fraction of the energy input expelled to the cold reservoir is 0.25.
Correct answer: 0.75- A. -111 K
- B. 362 K
- C. 435 K
- D. 111 K
Explanation: K = C + 273162 C = (162 + 273) K = 435 K. To convert Celsius to Kelvin, you add 273.15 to the Celsius temperature.
Correct answer: 435 K- A. Ks=ℽkt
- B. Ks=kt/ℽ
- C. ks= kt
- D. ks=2kt
Explanation: An isothermal process has pV constant, and the derivative of this with respect to V gives dp/dV = -p/V , while for adiabatic, pVℽ is…
Correct answer: Ks=ℽkt- A. 121 x 1^5 Pa
- B. 1.21 x 1^5 Pa
- C. 1.21 Pa
- D. 121 Pa
Explanation: Using the Ideal Gas formula PV=nRT where R is the molar gas constant of 8.31 Joules, with the first set of values (temperature must be…
Correct answer: 1.21 x 1^5 Pa- A. Both
- B. Constant
- C. Variable
- D. Zero
- E. High
Explanation: A heat reservoir refers to a system or body that is capable of providing or absorbing an infinite amount of heat without undergoing a…
Correct answer: Constant- A. 123 K
- B. -123 K
- C. 423 K
- D. -423 K
Explanation: The temperature in Kelvin is 273° more than the temperature in Celsius. TK = 273 + T°C = 273 + (-150) = 123 K
Correct answer: 123 K- A. 3Vo
- B. 2Vo
- C. Vo/3
- D. Vo/2
Explanation: By boyle's law; V∝1/PIf V=Vo and P=3Po then Vo /3 ∝1/3PoSince pressure and volume of a gas are inversely proportional,therefore if…
Correct answer: Vo/3- A. 17 mc/L
- B. L/17 mc
- C. 17 m/Lc
- D. 290 m/Lc
Explanation: For Specific heat capacity, use the formula Q = mcΔT.And for the latent heat of fusion of ice, use the formula Q = ML.The heat that is…
Correct answer: 17 mc/L- A. 63 seconds
- B. 63 minutes
- C. 630 seconds
- D. 6.3 minutes.
Explanation: For specific heat capacity, use the formula Q = mcΔT.Heat required = (500)(4.2)(50-20).E = 63000J.Power is the amount of energy…
Correct answer: 630 seconds- A. Reversible
- B. Irreversible
- C. Depends on the conditions
- D. Conduction process
Explanation: The flow of heat energy from a hot body to a cold body is a natural, irreversible process according to the second law of thermodynamics.
Correct answer: Irreversible- A. 123⁰C
- B. -123⁰C
- C. 423⁰C
- D. -423⁰C
Explanation: Temperature in degrees Celsius + 273= Temperature in Kelvinx+273=150x= -273+150x= -123 C which is option B.
Correct answer: -123⁰C- A. 70oC
- B. 60oC
- C. 50oC
- D. 40oC
Explanation: We use the principle of conservation of energy, which states that the heat lost by the hotter substance (water) must equal the heat gained…
Correct answer: 60oC- A. They expand by the same amount
- B. The hollow sphere expands more
- C. The solid sphere expands more
- D. There is not enough information to say
Explanation: The formula for cubical expansion is change in volume= cubical expansion coefficient x initial volume x change in temperature.
Correct answer: They expand by the same amount- A. 28 min
- B. 16.7 min
- C. 2.8 min
- D. 167 min
Explanation: To melt 50 g of ice at 0°C, we need to supply energy equal to:Q = m × Lf where Q is the heat energy, m is the mass of ice, and Lf is the…
Correct answer: 2.8 min- A. 90 g
- B. 90 kg
- C. 1.5 kg
- D. 1.5 g
Explanation: To calculate the mass of ice that melts, we can use the formula:Q = m * Lwhere:Q = heat energy absorbed or released during a phase change…
Correct answer: 90 g- A. -223K
- B. 223K
- C. -323K
- D. 323K
Explanation: Correct Option: B To convert a temperature from Celsius (°C) to Kelvin (K), you need to add 273.15 to the Celsius value.So, to convert…
Correct answer: 223K- A. 80˚C, 37˚C
- B. 99˚C, 30˚C
- C. 99˚C, 25˚C
- D. 99˚C, 37˚C
Explanation: The efficiency of the engine = η = Work / Qinput.As W = ⅙ QinputAlso η = 1 - T2/T1 T1 and T2 are the temperatures of source and sink.⅙ = 1…
Correct answer: 99˚C, 37˚C