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 4 of 14
- A. Fahrenheit
- B. Centigrade
- C. Kelvin
- D. None
Explanation: The Kelvin scale is an absolute temperature scale that is independent of the properties of any specific substance.
Correct answer: Kelvin- A. 323 K
- B. 50 K
- C. 223 K
- D. 70 K
Explanation: The Kelvin temperature is obtained by adding 273.15 to the Celsius temperature. Therefore, 50°C + 273.15 = 323.15 K.
Correct answer: 323 K- A. 100 K, 80 K
- B. 80 K, 60 K
- C. 40 K, 20 K
- D. 60 K, 40 K
Explanation: The efficiency of Carnot's engine depends on the temperature difference between the hot and cold reservoirs.
Correct answer: 100 K, 80 K- A. it is independent of nature of working substance
- B. it is linear over a wide range of temperature
- C. it is based on triple point of water
- D. none
Explanation: This is indeed the key advantage of the Kelvin scale. Unlike the Celsius and Fahrenheit scales, which are defined based on specific…
Correct answer: it is independent of nature of working substance- A. 1:2
- B. 2:3
- C. 3:4
- D. 8:9
Explanation: Here's how to solve this problem and find the ratio of their linear expansions:1.
Correct answer: 8:9- A. Air conditioner
- B. Desert cooler
- C. Room cooler
- D. Projector
Explanation: A desert cooler, also known as an evaporative cooler, is a device that uses the principle of evaporative cooling to lower the temperature…
Correct answer: Desert cooler- A. Absorbers
- B. Emitters
- C. Reflectors
- D. None of these
Explanation: White clothes are good reflectors of light and heat. This means that they reflect most of the sunlight that falls on them, rather than…
Correct answer: Reflectors- A. Increases
- B. Decreases
- C. Remains Same
- D. Decreases then suddenly increases
Explanation: When a system absorbs heat from its surroundings, it gains thermal energy.
Correct answer: Increases- A. 574
- B. 674
- C. 474
- D. 364
Explanation: The heat of vaporization is the amount of heat energy required to convert a unit mass of a substance from a liquid to a gas at its boiling…
Correct answer: 574- A. Temperature
- B. Pressure
- C. Entropy
- D. Energy Conservation
Explanation: The prefix "iso-" means "same" or "constant," and "thermal" relates to heat or temperature.
Correct answer: Temperature- A. 6.68 × 10⁵ J
- B. 6.68 x 10⁵ kJ
- C. 668 J
- D. 6688 kJ
Explanation: The heat required for a phase change is given by Q = mL, where m is the mass and L is the specific latent heat.
Correct answer: 6.68 × 10⁵ J- A. 1260 W
- B. 12.6 kW
- C. 210 W
- D. 12.6 W
Explanation: First, find the heat energy required: Q = mcΔT = (500 g) × (4.2 J/g°C) × (50°C - 20°C) = 63,000 J.
Correct answer: 210 W- A. 28 min
- B. 16.7 min
- C. 2.8 min
- D. 167 min
Explanation: First, calculate the total heat needed: Q = mL = (50 g) × (334J/g) = 16,700 J. The heater provides power (P) of 100 W, which is 100 J/s.
Correct answer: 2.8 min- A. 62 min
- B. 62 sec
- C. 1.5 hour
- D. 0.5 hour
Explanation: First, calculate the total heat energy required: Q = mL = (500 g) × (2230 J/g) = 1,115,000 J. The heater power (P) is 300 W (300 J/s).
Correct answer: 62 min- A. Coefficient of linear expansion
- B. Coefficient of volume expansion
- C. Ideal gas constant
- D. Specific heat of a substance
Explanation: The law of heat exchange states that heat lost by the hot body = heat gained by the cold body.
Correct answer: Specific heat of a substance- A. 1 K
- B. 100 K
- C. 273.16 K
- D. 0 K
Explanation: The triple point of water is the specific temperature and pressure where water can coexist in solid, liquid, and gaseous phases.
Correct answer: 273.16 K- A. Isothermal
- B. Adiabatic
- C. Isovolumetric
- D. Isobaric
Explanation: An isothermal process is a thermodynamic process in which the temperature of a system remains constant (ΔT = 0).
Correct answer: Isothermal- A. 98.6º
- B. 40º
- C. 37º
- D. 459.4º
Explanation: The normal human body temperature is approximately 37°C on the Celsius (centigrade) scale.
Correct answer: 37º- A. Zeroth law of thermodynamics
- B. Second law of thermodynamics
- C. First law of thermodynamics
- D. Third law of thermodynamics
Explanation: The Zeroth Law of Thermodynamics establishes the concept of thermal equilibrium.
Correct answer: Zeroth law of thermodynamics- A. Heat and surrounding
- B. Heat and other forms of energy
- C. Heat and liquid
- D. Heat and chemical energy
Explanation: Thermodynamics is the branch of physics that deals with the relationships between heat, work, and temperature, and their relation to…
Correct answer: Heat and other forms of energy