Free Thermal Equilibrium and Heat MCQs with Answers
277 Thermal Equilibrium and Heat 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 means that bodies in contact have the same temperature and no net heat flows between them. The topic distinguishes heat from temperature, uses the zeroth law of thermodynamics, and covers heat transfer, specific heat capacity, thermal expansion and the conditions for reaching equilibrium.
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277 questions · page 7 of 14
- A. Non-spontaneous reaction
- B. Endothermic process
- C. Exothermic process
- D. Isothermic process
Explanation: Endothermic processes are the ones that absorb heat from the surroundings.
Correct answer: Endothermic process122. The plot of pressure on the Y axis and volume on the X axis, at constant temperature is called:
- A. None of these
- B. Isochor
- C. Isotherm
- D. Isobar
Explanation: The volume-pressure graph at contant temperature is called an isotherm.
Correct answer: Isotherm- A. 1.49 kJ
- B. 2.51 kJ
- C. 1.85 kJ
- D. 2.98 kJ
Explanation: The Carnot cycle efficiency is calculated using the formula: η = 1 − (Tsink / Tsource), with temperatures in Kelvin.
Correct answer: 1.49 kJ- A. Total heat
- B. Work done
- C. Entropy
- D. Both a and c
Explanation: In an adiabatic process, the quantity that remains constant is the entropy and total heat.The term "adiabatic" refers to a process in…
Correct answer: Both a and c- A. Isochoric
- B. Isothermal
- C. Adiabatic
- D. Isobaric
Explanation: In an "adiabatic" process there is no exchange of heat. Hence option C is the correct answer.
Correct answer: Adiabatic- A. It depends on condition
- B. Not always
- C. True
- D. False
Explanation: It is true because the transfer of heat through convection depends on several factors, such as the temperature difference between the two…
Correct answer: False- A. 4.18 J
- B. 4180 J
- C. 2.09 J
- D. 2090 J
Explanation: One Kcal = 4.18 KJ or 4180 JOne kilocalorie (kcal) is equal to 4,184 joules.
Correct answer: 4180 J- A. 80˚C, 37˚C
- B. 99˚C, 30˚C
- C. 99˚C, 25˚C
- D. 99˚C, 37˚C
Explanation: Efficiency = T2-T1/T2 = ⅙ By rearranging we can get 6T2-6T1 = T2 T2 = 1.2T1T2 is the source and T1 is the sink.
Correct answer: 99˚C, 37˚C- A. We can not achieve the higher temperature
- B. We do not have an ideal working substance
- C. There are always enegy losses
- D. We need cold resevoir at absolute zero temperature, which is not available
Explanation: The efficiency of a Carnot engine is defined as the ratio of the work output to the heat input.
Correct answer: We need cold resevoir at absolute zero temperature, which is not available- 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