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 26 of 36
- A. 98.6 oF
- B. 40 oC
- C. 37 oC
- D. 459.4 oC
Explanation: Option A: A temperature of 98.6 degrees Fahrenheit is equivalent to 37 degrees Celsius.
Correct answer: 37 oC502. One kcal = _.
- A. 4.18 J
- B. 4180 J
- C. 2.09 J
- D. 2090 J
Explanation: A calorie is defined as the amount of energy required to raise the temperature of one gram of water by one degree Celsius.
Correct answer: 4180 J- A. 1260 W
- B. 12.6 kW
- C. 210 W
- D. 12.6 W
Explanation: t= 5 min = 5*60 = 300 secm= 500 gΔT change in temperature = 50°C-20°C = 30°Cc= 4.2Q [heat supplied/energy] = mcΔT = 500*4.2*30 = 63,000 J…
Correct answer: 210 W- A. Reversible
- B. Irreversible
- C. Depends on the conditions
- D. Conduction process
Explanation: In heat conduction, heat is transferred from one place to another. This process is not reversible.
Correct answer: Irreversible- A. 28 min
- B. 16.7 min
- C. 2.8 min
- D. 167 min
Explanation: Given : Power = 100 watt Specific latent heat of fusion = L = 334 j/g M = 50 g Since we know that Q= ml Where Q is the heat energy ,thus…
Correct answer: 2.8 min- A. 90 g
- B. 90 kg
- C. 1.5 g
- D. 1.5 kg
Explanation: Q = ml Q = E = pt 100 x 5 x 60 = 30,000J 30,000 = m x 334 m = 30,000/334 = 89.8 ≈ 90g approximately.
Correct answer: 90 g- A. -223K
- B. 223K
- C. -323K
- D. 323K
Explanation: Conversion of Temperature from Celsius to Kelvin:TK = TC + 273TK = -50oC + 273TK = 223 KHence, B is the correct option.
Correct answer: 223K- A. 140°C
- B. 60°C
- C. 0.2°C
- D. 14°C
Explanation: Power = 100 WWeight of water = 500 g Time = 5 min specific heat = 4.2 J/ gC use formula p × t = m*s*δ t (100 × 5 × 60) j = 500 g × 4.2…
Correct answer: 60°C- A. Infinite
- B. Zero
- C. Double the temperature
- D. None of these options are correct
Explanation: Option B is correct since if the temperatures of the two bodies are equal, there will be no transfer of heat energy as heat is an energy…
Correct answer: Zero- 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: According to combined gas law, P1V1/T1 = P2V2/T2, The volume is constant so we can say that pressure and temperature are directly…
Correct answer: Pressure increases by a factor of 4- A. volume
- B. pressure
- C. molecule type
- D. absolute temprature
Explanation: In the kinetic theory of gases, temperature is directly related to the average kinetic energy of the gas molecules.
Correct answer: absolute temprature- A. 8.314 J mol-31K-3
- B. 1.38J mole-1 K-3
- C. 1.38J mole-1 K-1
- D. 8.314 J mole-1 K-1
Explanation: Physically, the gas constant is the constant of proportionality that relates the energy scale in physics to the temperature scale, when a…
Correct answer: 8.314 J mole-1 K-1- A. NR/p
- B. NRp
- C. Nk/p
- D. Nkp
Explanation: We know that PV= NkT where P is the pressure and k is the Boltzman constant PV= NkT V= NkT/P V= (Nk/P)T (1) Equation of a straight line =Y…
Correct answer: Nk/p- A. Volume decreased, temperature decreased
- B. Volume decreased, temperature increased
- C. Volume increased, temperature decreased
- D. Volume increased, temperature increased
Explanation: An experimental gas law that describes the relationship between pressure and volume of a confined (Boyle's Law).
Correct answer: Volume increased, temperature decreased- A. 77°C
- B. -77°C
- C. 623 °C
- D. -623 °C
Explanation: Correct option is A. C = K - 273.15 C=350 K-273.15 C=76.85 degrees celsius As this is a numerical thus it can only have one correct option.
Correct answer: 77°C- A. Conduction only
- B. Convection only
- C. Radiation only
- D. None of these
Explanation: Initially, the water in the lake is cooled by convection as colder air makes contact with the water's surface, causing the surface water…
Correct answer: Conduction only- A. Convection
- B. Conduction
- C. Radiation
- D. Conduction and convection both
Explanation: The correct answer is convection. In this scenario, the heat from the warmer water is transferred to the ice cube primarily through…
Correct answer: Convection- A. The rubber pipe expanded when heated, allowing it to fit over the tap
- B. The plastic tap deformed due to the heat from the hair dryer
- C. Heat caused a chemical reaction leading to adhesion between the rubber and plastic
- D. None of the above options are correct
Explanation: The correct answer is that the rubber pipe expanded due to the heat from the hair dryer.
Correct answer: The rubber pipe expanded when heated, allowing it to fit over the tap- A. 3/2 α
- B. 5/2 α
- C. 5/3 α
- D. None of these
Explanation: To find the average coefficient of linear expansion for the composite rod, we calculate a weighted average based on the lengths of the…
Correct answer: 5/3 α- A. 7/8
- B. 8/7
- C. 3/8
- D. 5/8
Explanation: In an insulated system, the energy lost by the water that freezes must equal the energy required to vaporize the remaining water.
Correct answer: 7/8