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 8 of 14
- 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- 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