Free Thermal Equilibrium and Heat MCQs with Answers

• A. efficiency
• B. coefficient of performance
• C. both a and b
• D. not describe

Explanation: A heat engine works by utilizing a cyclic process, where it continuously operates in a repeating sequence.Additionally, a heat engine…

• A. Escape of air from burst tyre
• B. Cloud formation
• C. Slow expansion
• D. Rapid compression

Explanation: Cloud formation is not an adiabatic process. It involves various processes such as condensation and evaporation, which typically involve…

• A. All heat can be converted to work
• B. Heat flows spontaneously from hot to cold
• C. Internal energy is always conserved
• D. Work cannot be converted to heat

Explanation: The second law states that heat flows spontaneously from a hotter body to a colder one, increasing the entropy of the universe, unless…

• A. Boyle's law
• B. Isothermal process
• C. General gas law
• D. Charles's law
• E. Henry's law

Explanation: Charles's law, discovered by Jacques Charles, states that for a fixed amount of gas at constant pressure, the volume is directly…

• A. 500 mm of Hg
• B. 900 mm of Hg
• C. 1,100 mm of Hg
• D. 1,270 mm of Hg
• E. 1,500

Explanation: Solution: This problem can be solved by ideal gas equation; PV=nRTSince, the temperature remains constant, therefore: Given: Initial…

• A. Zeroth law of thermodynamics
• B. 1st law of thermodynamics
• C. 2nd law of thermodynamics
• D. 1st and 2nd law of thermodynamics

Explanation: According to this law,it's impossible for an engine to extract heat from a hot reservoir and convert it completely into useful work.

• A. The pressure exerted by a gas is proportional to mean square velocity of the molecules
• B. The pressure exerted by the gas is proportional to the root mean square velocity of the molecules
• C. The root mean square velocity is inversely proportional to the temperature
• D. The mean translational K.E. of the molecule is directly proportional to the absolute temperature

Explanation: "The equation KE=(3RT)/(2Nٖₐ) gives a new definition of temperature according to which the kelvin temperature of a gas is directly…

• A. 98.6
• B. 40
• C. 37
• D. 459.4

Explanation: Option A: A temperature of 98.6 degrees Fahrenheit is equivalent to 37 degrees Celsius.

• A. 6.68 x 10^5 J
• B. 6.68 x 10^5 kJ
• C. 668 J
• D. 6688 kJ

Explanation: m=2 kg , L=332J/gQ=mLQ=(2×1000)(332)Q=(2000)(332)Q=664000Q=6.64×105 J

• A. Energy travels from the larger object to the smaller object
• B. Energy travels from the object with more mass to the one with less mass
• C. Energy travels from the object at higher temperature to the object at lower temperature
• D. Energy does not travel

Explanation: If two objects at different temperatures are brought in contact with each other, energy is transferred from the hotter object (that is…

• A. 1 K
• B. 100k
• C. 273.16k
• D. 0K

Explanation: The triple point of pure water is at 0.01°C (273.16K, 32.01°F)

• A. 1.5 kg of the material is to be heated by 7.0 C°
• B. 3.0 kg of the material is to be heated by 3.5 C°
• C. 0.50 kg of the material is to be heated by 21 C°
• D. The amount of heat required is the same in each of the three previous cases

Explanation: When an object is heated, it's temperature changes over a period of time.

• A. 62 mins
• B. 62 secs
• C. 1.5 hour
• D. 0.5 hour

Explanation: Option A is correct since we know that,P = Q/t t = Q/ Pt= mc / pSo t = 500 x 2230 / 300 = 3717s t = 3717 / 60 = 62 mins

• A. Work
• B. Enthalpy
• C. Internal energy
• D. Pressure

Explanation: The thermodynamic state of a system refers to the temperature, pressure and quantity of substance present.

• A. not constant
• B. constant
• C. zero
• D. proportional

Explanation: According to Boyle's law, which applies to an ideal gas undergoing an isothermal process, the product of pressure and volume remains…

• A. Non-spontaneous reaction
• B. Endothermic process
• C. Exothermic process
• D. Spontaneous reaction

Explanation: Endothermic processes are the ones that absorb heat from the surroundings.

• A. 1/Kg
• 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.Option A is incorrect since the value…

• A. 3.23 x 10^-21 J
• B. 4.11 x 10^-21 J
• C. 6.21 x 10^-21 J
• D. 7.71. x 107-21 J
• E. 9.11 x 10^7-21 J

Explanation: To calculate the average translational kinetic energy of molecules in a gas at a given temperature, we can use the equation:K.E.

• A. The pipe expanded due to the hot air, and then contracted back again
• B. The tap got deformed because of the hot air
• C. The hot air caused adhesion between the rubber and plastic
• D. None of the above options are correct

Explanation: Applying heat from the hair dryer caused the rubber pipe to expand due to the increase in temperature.

• A. Water equivalent
• B. Temperature gradient
• C. Thermal capacity
• D. Specefic heat

Explanation: Option C is correct.The heat that is given to a body that raises its temperature by 1°C is the thermal capacity of the body.Thermal…