Download Sample Problems in Thermodynamics and more Exercises Thermodynamics in PDF only on Docsity!
THERMODYNAMICS
- How many independent properties are required to completely fix the equilibrium state of a pure gaseous compound?
a. 4 b. 3 c. 2 d. 1
Answer: C
- What is the value of the work done for a closed, reversible isometric system?
a. zero b. positive c. negative d. positive or negative
Answer: A
- The first law of thermodynamics is based on which of the following principles?
a. Conservation of mass b. Conservation of energy c. Action and reaction d. The entropy-temperature relationship
Answer: B
- Which of the following cycle is used in vapor cycle power plant?
a. Brayton cycle b. Diesel cycle c. Ericson cycle d. Rankine cycle
Answer: D
- Which of the following is not a thermodynamic property?
a. Pressure b. Temperature c. Volume d. Phase
Answer: D
- Which of the following compressibility factor of ideal gas
a. 1 b. 2 c. 1. d. 0
Answer: A
- What refers to the thermodynamic properties which are dependent on the amount of the substance present?
a. Extensive property b. Intensive properties c. Reversible properties d. Irreversible properties
Answer: A
- What refers to the thermodynamic properties which are independent on the amount of the substance present?
a. Extensive property b. Intensive properties c. Reversible properties d. Irreversible properties
Answer: B
- What is known as the total heat and heat content at various times in the history?
a. enthalpy b. entropy c. internal energy d. latent heat
Answer: A
- What is the measure of the energy that is no longer available to perform useful work within the current environment?
a. enthalpy b. entropy c. internal energy
a. Kilojoule b. Btu c. Kilocalorie d. Latent heat
Answer: C
- To what conditions does a gas behave like an ideal gas?
a. low temperature and low pressure b. low temperature and high pressure c. high temperature and low pressure d. high temperature and high pressure
Answer: C
- What Law states that the pressure of gas is inversely proportional to its volume at constant temperature?
a. Charles’ law b. Gay-Lussac’s Law c. Boyle’s Law d. Dalton’s Law
Answer: C
- What do you call a system in which there is a flow of matter through the boundary?
a. Closed sysytem b. Open system c. Isolated sysytem d. All of these
Answer: B
- Which of the following best describes heat?
a. The capacity to do work b. Forces times distances c. Sum of thermal and chemical energy d. An energy transfer due to temperature difference
Answer: D
- The mechanical equivalent of heat is
a. joule b. calorie c. Btu d. Specific heat
Answer: A
- Burning of Gasoline initially requires heat before it burns spontaneously. Which of the following does not give a good explanation of this phenomenon?
a. the initial heat rises the enthalpy of the reactant b. the initial heat lowers the activation of energy of the reactants c. the enthalpy of reactants is lower than the enthalpy of products. d. The enthalpy of the product is lower than the enthalpy of the reactant
Answer: C
- The phenomenon of melting under pressure and freezing again when the pressure is reduced is known as
a. sublimation b. condensation c. deposition d. regelation
Answer: D
- Which of the following events is heat exchange involved?
a. when there is a phase change b. when there is a chemical reaction c. when the gas expands adiabatically d. when there is difference in temperature
Answer: C
- What is the entropy of a pure substance at a temperature of absolute zero?
a. unity b. zero c. infinity d. undefined
Answer: B
Answer: D
- Which of the following best describes both Stirling and Ericson engines?
a. Internal combustion engine b. External combustion engine c. Diesel cycle d. Rankine cycle
Answer: B
- At steam point, the temperature of water and its vapour at standard pressure are:
a. Extremes or maximum b. unity c. in equilibrium d. undefined
Answer: C
- Who coined the word Entropy?
a. Rudolf Clausius b. Lord Kelvin c. Gabriel Volks d. Rudolf Diesel
Answer: A
- What is the temperature when water and vapor are in equilibrium with the atmospheric pressure?
a. Ice point b. Steam point c. Critical point d. Freezing point
Answer: B
- When the expansion of compression of gas takes place without transfer of heat to or from the gas the process is called
a. reversible b. adiabatic c. polytropic
d. isothermal
Answer: B
- What refers to a liquid whose temperature is lower than saturation temperature corresponding to the exisitng pressure?
a. Subcooled liquid b. Saturated liquid c. Pure liquid d. Compressed liquid
Answer: A
- Which law that states “Entropy of all perfect crystalline solids is zero at absolute zero temperature”?
a. Zeroth law of thermodynamics b. First law of thermodynamics c. Second law of thermodynamics d. Third law of thermodynamics
Answer: D
- A 0.064 kg of octane vapor (MW = 114) is mixed with 0.91 kg of air (MW = 29.0) in the manifold of an Engine. The total pressure in the manifold is 86.1 kPa, and a temperature is 290 K. assume octane behaves ideally. What is the partial pressure of the air in the mixture in KPa?
a. 46. b. 48. c. 84. d. 64.
Answer: C
- Which of the following occurs in a reversible polytropic process?
a. Enthalpy remains constant b. Internal energy does not change c. Some heat transfer occurs d. Entropy remains constant
Answer: C
Answer: C
- Which of the following is used in thermal power plant?
a. Brayton cycle b. Reversed carnot cycle c. Rankine cycle d. Otto cycyle
Answer: C
- A Bell-Coleman cycle is a reversed of which the following cycles?
a. Stirling cycle b. Joule cycle c. Carnot cycle d. Otto cycle
Answer: B
- An ideal gas is compresses isothermally. The enthalpy change is
a. Always negative b. Always positive c. zero d. undefined
Answer: C
- The state of a thermodynamic system is always defined by its:
a. Absolute temperature b. process c. properties d. temperature and pressure
Answer: C
- Entropy is the measure of:
a. The internal energy of a gas b. The heat capacity of a substance c. Randomness or disorder d. The change of enthalpy of a system
Answer: C
- What system in which there is no exchange of matter with the surrounding or mass does not cross its boundaries?
a. Open system b. Closed system c. Isolated system d. Non-flow system
Answer: B
- What refers to a system in which there is a flow of mass across its boundaries?
a. Open system b. Closed system c. Isolated system d. Non-flow system
Answer: A
- Which of the following cannot be a property of a gas?
a. density b. pressure c. viscosity d. temperature
Answer: C
- During the adiabatic process, which of the following is the change in entropy?
a. zero b. greater than zero c. less than zero d. infinity
Answer: A
- Which of the following values characterize the state of the system?
a. cycle b. process c. property d. enthalpy
Answer: D
- Which of the following is the other term used for enthalpy-entropy diagram?
a. Enthalpy diagram b. Mollier diagram c. Steam diagram d. Entropy chart
Answer: B
- What is used for predicting the behavior of non-ideal gases?
a. Compressibility factor b. Expansivity factor c. Emissivity factor d. Van-d-whal’s factor
Answer: A
- Which of the following thermodynamic devices operates the reverse of the heat engine?
a. Thermal pump b. Thermal evaporator c. Thermal condenser d. Thermal equilibrant
Answer: A
- What is another term used for isometric processes?
a. Isochoric process b. Iolytropic process c. Isothermal process d. Reversible process
Answer: A
- Which of the following engines was introduced by a German engineer, Nickolas Otto?
a. Gasoline engine b. Diesel engine c. Gas turbine d. Thermal engine
Answer: A
- If two systems are in the thermal equilibrium with a third system, then they must be in thermal equilibrium with each other.
a. Zeroth Law of Thermodynamics b. First Law of Thermodynamics c. Second Law of Thermodynamics d. Third Law of Thermodynamics
Answer: A
- The heat absorbed by a unit mass of a material at its holding point in order to convert the material into a gas at the same temperature.
a. Latent Heat of Sublimation b. Latent Heat of Vaporization c. Latent Heat of Fusion d. Latent Heat Of Condensation
Answer: B
- A thermodynamic process in which entropy is conserved
a. isentropic b. adiabatic c. isothermal d. polytropic
Answer: A
- A control volume refers to what?
a. A fixed region in space b. A reversible process c. an isolated system d. a specified mass
Answer: A
- Which of the following is commonly used as liquid absorbent?
a. Silica gel b. Activated alumina c. Ethylene glycol
d. is basically zero
Answer: B
- Occuring at fixed temperature
a. isentropic b. Adiabatic c. Isothermal d. polytropic
Answer: C
- The changing of solid directly to vapor without passing through liquid state is called
a. Evaporation b. Vaporization c. Sublimation d. Condensation
Answer: C
- The phase transition of a liquid to a solid
a. Solidification b. Freezing c. Fusion d. All of these
Answer: D
- It is an energy flux, equal to the rate of energy flow per unit area per unit time across some surface.
a. Irradiance b. Radiant Intensity c. Luminosity d. Brightness
Answer: C
- The volume of a gas under constant pressure increases or decrease with temperature.
a. Gay- Lussac’s Law
b. Ideal Gas Law c. Charles’ Law d. Boyle’s Law
Answer: C
- The molecular number density of an ideal gas at standard temperature and pressure in cm^3
a. Froude number b. Loschmidt number c. Mach number d. Reynold number
Answer: B
- A temperature scale whose zero point is absolute zero, the temperature of “0” entropy at which all molecular motion stops.
a. Celsius b. Fahrenheit c. Kelvin d. Rankine
Answer: C
- The thermal radiation emitted by a blackbody heated to a given temperature.
a. Gamma Radiation b. Black Body Radiation c. Electromagnetic Radiation d. Alpha Radiation
Answer: B
- The radiation emitted by a body as a result of its temperature.
a. Blackbody Radiation b. Thermal Inversion c. Thermionic Inversion d. Thermal Radiation
Answer: D
- At Equilibrium, the radiation emitted must equal the radiation absorbed.
- This law of thermodynamics prohibits the construction of a perpetual motion machine “of the second kind”
a. Zeroth Law of Thermodynamics b. First Law of Thermodynamics c. Second Law of Thermodynamics d. Third Law of Thermodynamics
Answer: C
- A cylinder contains oxygen at a pressure of 10 atm and a temperature of 300 K. The volume of the cylinder is 10 liters. What is the mass of the oxygen in grams? Molecular weight (MW) of oxygen is 32g/mole?
a. 125. b. 130. c. 135. d. 120.
Answer: B {(10atm)(10)(32)/(0.0821)(300K)}
- It is the deposition of radiant energy as heat into an absorbing body.
a. Radiation b. Ionization c. Convection d. Insolation
Answer: D
- It is a process during which the pressure remains constant
a. Adiabatic b. Isentropic c. Isobaric d. Isotropic
Answer: C
- Diffusion due to thermal motion is called
a. dilation b. infusion c. effusion d. dispersion
Answer: C
- The rate at which this is quantity passes through a fixed boundary per unit time
a. Flux b. Existence c. Irradiance d. All of these
Answer: D
- Energy can neither created nor destroyed. It can only change forms.
a. Conservation of Mass Principle b. Conservation of Energy Principle c. Conservation of Momentum Principle d. Conservation of Heat Principle
Answer: B
- Executes the entire cycle in just two strokes the power stroke and the compression stroke.
a. One-stroke engine b. Two-stroke engine c. Four-stroke engine d. Eight-stroke engine
Answer: B
- It is the unbalanced force developed in a turbo jet engine that is caused by the difference in the momentum of the low-velocity air entering the engine and the high velocity exhaust gases leaving the engine. a. Fall b. Lift c. Drag d. Thrust
Answer: D
- Which of the engine is used for fighter bombers?
a. Turbojet b. Pulsejet c. Rockets d. Ramjet
