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 9 of 14
- 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- A. Pressure
- B. Universe
- C. Boundary
- D. Temperature
Explanation: The mass or region outside the system is called the surroundings, and the surface that separates the system and the surroundings is called…
Correct answer: Boundary- A. Momentum, 1 degree C
- B. Heat, 1 degree C
- C. Heat, 2 degree C
- D. Work, 2 degree C
Explanation: Heat capacity is defined as the amount of heat energy required to raise the temperature of a given quantity of matter by one degree…
Correct answer: Heat, 1 degree C- A. Pressure
- B. Volume
- C. Temperature
- D. Mass
Explanation: Thermal equilibrium between two systems is determined by the equality of temperature, as stated by the Zeroth Law of Thermodynamics.
Correct answer: Temperature- A. be doubled.
- B. remain constant
- C. be 1/2 of the original value
- D. be 1/4 of the original value
Explanation: Density is defined as the mass of a substance divided by its volume, mathematically expressed as ρ = m/V.
Correct answer: be 1/2 of the original value- 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. Boyle's law
- B. Charle's law
- C. Avogadro's law
- D. Law of heat exchange
Explanation: Boyle's law gives the relation between pressure and volume at constant temperature (isotherm).
Correct answer: Boyle's law- A. Isochoric process
- B. Adiabatic process
- C. Isobaric process
- D. Isothermal process
Explanation: An isobaric process is a thermodynamic process in which pressure stays constant i.e ΔP=0.An isochoric process is a thermodynamic process…
Correct answer: Isobaric process- A. [M1 L2 T-2 K-1]
- B. [M1 L-3 T-1 K-1]
- C. [M1 L-2 T-1 K-1]
- D. [M1 L-3 T-2 K-1]
Explanation: The ideal gas equation is:PV=nRTWhere:P is pressure with dimensions [ML−1T−2]V is volume with dimensions [L³][n is the number of moles…
Correct answer: [M1 L2 T-2 K-1]- A. Heat Capacity
- B. Heat Volume
- C. Heat Conductor
- D. Heat energy/ unit volume
Explanation: Heat capacity (C) is the amount of thermal energy required to raise the temperature of a substance by one unit (usually one degree Celsius…
Correct answer: Heat Capacity- A. It will expand due to expansion of the air molecules
- B. It will deflate due to contraction of the air molecules
- C. Its size will not be affected by the change in temperature
- D. It will burst.
Explanation: When the football is inflated in a warm room, the air molecules inside the ball are moving rapidly and are spaced farther apart, occupying…
Correct answer: It will deflate due to contraction of the air molecules180. When a gas is compressed isothermally, the product of its pressure and volume during the process is:
- A. Not constant
- B. Constant
- C. Proportional to temperature
- D. Proportional to entropy
Explanation: PV=constant holds for an ideal gas during isothermal compression
Correct answer: Constant