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 24 of 36
- A. 100
- B. 200
- C. 300
- D. 800
Explanation: Power consumption by liquid is Q = m x s x ∆ T= 1 x 4000x 80= 3.2 x 10⁵ jpower used = Q /t = 3.2 x 10⁵ / 400= 8 x 10² = 800Waverage power…
Correct answer: 200- A. 62min
- B. 62 sec
- C. 1.5 hour
- D. 0.5 hour
Explanation: t = Q/P= m x lf/P= 500 x 2230/300 = 3717 seconds = 62 minutes
Correct answer: 62min- A. 1.96 x 10^5 J
- B. 4.04 X 10^5 J
- C. 1.07 X 10^5 J
- D. 8.15 x 10^4 J
Explanation: According to formula of Specific Heat Capacity ( c ), c = Q / m T Rearranging for Heat Energy ( Q ), Q = c m T Q = 128 x 5 x ( 327-20 ) Q…
Correct answer: 1.96 x 10^5 J- A. 62 mins
- B. 62 sec
- C. 1.5 hour
- D. 0.5 hour
Explanation: Option A is correct. Heat energy required is found by Q=m x LQ= 500 X 2230 = 1115000 JoulePower= Q/T1115000 J / 300 W X 60 s = 61.9 minutes
Correct answer: 62 mins- A. Number of molecules per unit volume increases
- B. Molecules occupy a greater volume of the container
- C. Average force per impact at the container wall increases
- D. Molecules collide with each other with greater force
Explanation: In ideal gas the pressure is due to the collision of gas atoms with walls of the container.
Correct answer: Average force per impact at the container wall increases- A. P and V
- B. P and T
- C. T and V
- D. P and R
Explanation: Option D is correct as to find the state of the thermodynamic system, we need "P", "V", or "T". If we have any two, we can find the state.
Correct answer: P and R- A. K
- B. 1/K
- C. K2
- D. No unit
Explanation: K is the units of the ratio: specific latent heat of vaporization of water/ specific heat capacity of water .
Correct answer: K- A. 1J/K.g
- B. 4.18 J/Kg.K
- C. 4180 J/kg.K
- D. 2090 J/kg.K
Explanation: Option C is correct since 4180 J/Kg K is the correct value of the specific heat capacity of water.
Correct answer: 4180 J/kg.K- A. infinite
- B. zero
- C. double the temperature
- D. none of these
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. Work
- B. Energy
- C. Thermal equilibrium
- D. Entropy
Explanation: The zeroth law of thermodynamics is related to thermal equilibrium. This law establishes the concept of temperature and allows us to…
Correct answer: Thermal equilibrium- A. 7 seconds
- B. 420 seconds
- C. 8 minutes
- D. 420 minutes
Explanation: The formula for the amount of heat required to heat a substance is: Q = m × c × ΔTwhere Q is the amount of heat, m is the mass of the…
Correct answer: 420 seconds- A. R
- B. nR/P
- C. P
- D. R/P
Explanation: According to ideal gas law; PV = nRTRearranging the formula; V/T = nR/P
Correct answer: nR/P- A. Irreversible changes
- B. Chemical changes
- C. Cyclic changes
- D. Reversible changes
Explanation: Option A is correct since the transfer of heat by radiation, transfer of heat by conduction, and convection are irreversible reactions as…
Correct answer: Irreversible changes- A. Heat is converted to internal energy
- B. Heat is converted to only potential energy of the particles
- C. Heat is converted only kinetic energy of the particles
- D. Heat is converted to temperature of gas
Explanation: Option A is correct since when heat is added to a substance, the energy associated with the motion and configuration of its atoms or…
Correct answer: Heat is converted to internal energy- A. 33.4 J
- B. 33.4 kJ
- C. 3.34 J
- D. 3.34 kJ
Explanation: Correct Option: BTo calculate the energy needed to melt 100 g of ice at 0°C, we need to use the specific latent heat of fusion of ice…
Correct answer: 33.4 kJ- A. 1 kg
- B. 2 kg
- C. 3 kg
- D. 4 kg
Explanation: Q = mLwhere Q is the amount of thermal energy required to melt the ice, m is the mass of ice, and L is the specific latent heat of fusion…
Correct answer: 3 kg- A. 140˚C
- B. 40˚C
- C. 0.2˚C
- D. 14˚C
Explanation: Heat energy supplied will be Power x Time = 100 x 5 x 60 = 30000 J. Q = mcΔT hence ΔT = Q/mc = 30000/(500)(4.2) = 14˚C.
Correct answer: 14˚C- A. 140°C
- B. 40°C
- C. 0.2°C
- D. 14°C
Explanation: Heat energy supplied will be Power x Time = 100 x 5 x 60 = 30,000 J.Q = mcΔT hence ΔT = Q/mc = 30000/(500)(4.2) = 14°C.
Correct answer: 14°C- A. 28 minutes
- B. 16.7 minutes
- C. 2.8 minutes
- D. 167 minutes
Explanation: Q = mLf; where Q is the heat supplied, m is mass of ice, and Lf is the specific latent heat of fusion of ice.
Correct answer: 2.8 minutes- A. -100
- B. -40
- C. -180
- D. -273
Explanation: Water boils at temperatures=100°C, 212°F and water freezes at =0°C,32°F.
Correct answer: -40