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 22 of 36
- A. Pressure increases by a factor of 4
- B. Pressure decreases by a factor of 4
- C. Pressure decreases by a factor of 2
- D. Pressure increases by a factor of 2
- E. No change in pressure
Explanation: Option A: The pressure of the gas will increase by a factor of 4.This is because the ideal gas law states that the pressure of a gas is…
Correct answer: Pressure increases by a factor of 4- A. 359.4
- B. -459.4
- C. 100
- D. -259.4
Explanation: Absolute zero, is temperature at which a thermodynamic system has the lowest energy.
Correct answer: -459.4- A. P/cR
- B. PR/c
- C. Pc/R
- D. cPR
Explanation: Since Q=mctAnd according to the question, Q=P, c=c, and t=RWhen we place the values in the equation making m the subjectm=P/cR
Correct answer: P/cR- A. Decrease in the internal energy
- B. Increase in the internal energy
- C. Increase in the potential energy only
- D. Decrease in the kinetic energy only
Explanation: Heat, once absorbed as energy, contributes to the overall internal energy of the object.
Correct answer: Increase in the internal energy- A. It increases
- B. It decreases
- C. It remains the same
- D. It decreases with the square of temperature
Explanation: When the temperature increases, the length of the pendulum also increases and hence its time period increases.
Correct answer: It increases- A. 1.5 kg of the material is to be heated by 7.0 C0
- B. 3.0 kg of the material is to be heated by 3.5 C0
- C. 0.50 kg of the material is to be heated by 2 1 C0
- D. The amount of heat required is the same in each of the three previous cases
Explanation: Q=m x c x (change in temperature)Since the material is the same c does not change.
Correct answer: The amount of heat required is the same in each of the three previous cases- A. 77°C
- B. -77°C
- C. 623 °C
- D. -623 °C
Explanation: Correct option is A.C = K - 273.15C=350 K-273.15C=76.85 degrees celsiusAs this is a numerical thus it can only have one correct option.
Correct answer: 77°C- A. Energy travels from the larger object to the smaller object
- B. Energy travels from the object with more mass to the one with less mass
- C. Energy travels from the object at a higher temperature to the object at a lower temperature
- D. Energy does not travel
Explanation: Correct option is C.The energy travels from the object at higher temperature to the object at lower temperature.Equilibrium is the…
Correct answer: Energy travels from the object at a higher temperature to the object at a lower temperature429. How are clouds made?
- A. When water absorbs heat
- B. When ice melts
- C. When it is too hot
- D. When water releases heat
Explanation: Clouds are formed when water vapors condense to form water droplets (an exothermic process, so heat is released), which form a floating…
Correct answer: When water releases heat- A. Isochoric
- B. Isothermal
- C. Adiabatic
- D. Isobaric
Explanation: The living system works in isothermal conditions i.e the temperature of the body remains constant due to thermoregulatory mechanisms.
Correct answer: Isothermal- A. Calorie
- B. Kilojoule
- C. Joule
- D. Calories/gram
Explanation: The heat of vaporization (ΔHv) is defined as the energy (Q) required to vaporize 1g of a liquid without any change in its temperature.
Correct answer: Calories/gram- 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 process433. 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