Description : Steam is throttled to 0.1 MPa with 20 degrees of superheat. (a) What is the quality of throttled steam if its pressure is 0.75 MPa (b) What is the enthalpy of the process? a) 97.6%,2713 kJ/kg b) -97.6%, 2713 kJ/kg c) 87.6%,3713 kJ/kg d) -87.6%, 3713 kJ/kg
Last Answer : 97.6%,2713 kJ/kg
Description : 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
Last Answer : Randomness or disorder
Description : What refers to the measure of the disorder present in a given substance or system? A. Enthalpy B. Entropy C. Heat capacity D. Molar heat
Last Answer : Entropy
Description : Total heat of a substance is also known as (a) internal energy (b) entropy (c) thermal capacity (d) enthalpy (e) thermal conductance.
Last Answer : Answer : d
Description : 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 d. latent heat
Last Answer : entropy
Description : Why thermal efficiency of I.C. engines is more than that of gas turbine plant ?
Last Answer : In I.C. engine maximum temperature attained is higher than in gas turbine.
Description : What is the highest efficiency of heat engine operating between the two thermal energy reservoirs at temperature limits? A. Ericson efficiency B. Otto efficiency C. Carnot efficiency D. Stirling efficiency
Last Answer : Carnot efficiency
Description : What is defined as the ratio of the net electrical power output to the rate of fuel energy input? A. Combustion efficiency B. Thermal efficiency C. Overall efficiency D. Furnace efficiency
Last Answer : Overall efficiency
Description : Which statement of the second law of thermodynamics states that no heat engine can have a thermal efficiency of 100 percent? A. Kelvin-Planck statement B. Clausius statement C. Kevin statement D. Rankine statement
Last Answer : Kelvin-Planck statement
Description : Thermal efficiency is the ratio of: A. Network input to total heat input B. Network output to total heat output C. Network output to total heat input D. Network input to total heat output
Last Answer : Network output to total heat input
Description : Which of the following represents the perpetual motion of the first kind (a) engine with 100% thermal efficiency (b) a fully reversible engine (c) transfer of heat energy from low ... its own energy (e) production of energy by temperature differential in sea water at different levels.
Description : Boiler efficiency is a measure of how effectively _______ energy in fuel is converted into heat energy in steam going to the turbines A Chemical energy B Heat energy C Thermal energy D All of the above
Last Answer : A Chemical energy
Description : Walls of a cubical oven are of thickness l, and they are made of material of thermal conductivity k. The temperature inside the oven is 100°C and the inside heat transfer co-efficient is 3k/l'. If the wall temperature ... wall temperature in degree centigrade? (A) 35.5 (B) 43.75 (C) 81.25 (D) 48.25
Last Answer : (C) 81.25
Description : Hyperbolic cooling towers have become design standard for all natural draft structural towers because usage of . a. Their structural strength b. Minimum usage of material. c. Improving cooling efficiency d. All of the above.
Last Answer : All of the above.
Description : As compression ratio increases, thermal n increases. How is thermal n affected by weak and rich mixture strength ?
Last Answer : Thermal n is high for weak mixture and it decreases as mixture strength becomes rich.
Description : What is a measure of the ability of a material to conduct heat? A. Specific heat capacity B. Coefficient of thermal expansion C. Coefficient of thermal conductivity D. Thermal conductivity
Last Answer : Thermal conductivity
Description : Calorie is a measure of (a) specific heat (b) quantity of heat (c) thermal capacity (d)entropy (e) work.
Last Answer : Answer : b
Description : The amount of energy required to produce a given degree of pulverisation depends primarily on a) Soil strength b) Energy utilisation efficiency of tool c) Both (a) and (b) d) None of the above
Last Answer : c) Both (a) and (b)
Description : The maximum efficiency of a scres jack having square threads and friction angle of 30 degree will be a.0.2 b.0.11 c.0.05 d.0.33 e.0.09
Last Answer : d. 0.33
Description : The importance of the correlation co-efficient lies in the fact that: (A) There is a linear relationship between the correlated variables. (B) It is one of the most valid measure of statistics. ... of the association be tween two variables. (D) It is a non-parametric method of statistical analysis.
Last Answer : (C) It allows one to determine the degree or strength of the association be tween two variables.
Description : For a thermodynamic system undergoing a process, which of the following pairs best expresses the relationship similar to that expressed by the pressure volume plot? (A) Temperature - entropy (B) Temperature - pressure (C) Enthalpy - entropy
Last Answer : (A) Temperature - entropy
Description : Which of the following values characterize the state of the system? a. cycle b. process c. property d. enthalpy
Last Answer : enthalpy
Description : The change that the system that undergoes from one equilibrium state to another is known as a. oath b. process c. enthalpy change d. entropy change
Last Answer : process
Description : Sum of the internal energy of a substance and the product of pressure and volume. a. Specific Heat b. Specific Gravity c. Isolated System d. Enthalpy
Last Answer : Enthalpy
Description : A system having a rigid boundary that energy, work and mass does not cross its boundaries a. Specific Heat b. Specific Gravity c. Isolated System d. Enthalpy
Last Answer : Isolated System
Description : A function of state that is associated with disorder in the system and environment. a. enthalpy b. entropy c. law of diminishing return d. Lenz’ Law
Description : An adiabatic process in which there is no change in system enthalpy but for which there is a significant decrease in pressure is called _____. A. Isochoric process B. Isobaric process C. Throttling process D. Quasistatic process
Last Answer : Throttling process
Description : What is considered as the heat content of a system? A. Enthalpy B. Entropy C. Internal heat D. Molar heat
Description : Change in enthalpy in a closed system is equal to heat transferred if the reversible process takes place at constant (a) pressure (b) temperature (c) volume (d) internal energy (e) entropy.
Last Answer : Answer : a
Description : According to first law of thermodynamics (a) work done by a system is equal to heat transferred by the system (b) total internal energy of a system during a process remains constant ( ... , enthalpy and entropy during a process remain constant (d) total energy of a system remains constant
Description : Change in enthalpy of a system is the heat supplied at (a) constant pressure (b) constant temperature (c) constant volume (d) constant entropy (e) N.T.P. condition.
Description : Which of the following is the property of a system (a) pressure and temperature (b) internal energy (c) volume and density (d) enthalpy and entropy (e) all of the above.
Last Answer : Answer : e
Description : The efficiency of superheat Rankine cycle is higher than that of simple Rankine cycle because [GATE-2002] (a) The enthalpy of main steam is higher for superheat cycle (b) The mean temperature of heat ... temperature of steam in the condenser is high (d) The quality of stem in the condenser is low
Last Answer : (b) The mean temperature of heat addition is higher for superheat cycle
Description : The product of efficiency & heat transferred to the working fluid is? a. Net temperature change b. Net work done c. Net enthalpy change d. None of the mentioned
Last Answer : b. Net work done
Description : Pick out the wrong statement. (A) Minimum number of degree of freedom of a system is zero (B) Degree of freedom of a system containing a gaseous mixture of helium, carbon ... ) Enthalpy and internal energy change is zero during phase change processes like melting, vaporisation and sublimation
Last Answer : (D) Enthalpy and internal energy change is zero during phase change processes like melting, vaporisation and sublimation
Description : Define the terms free energy and free enthalpy. What is their significance and importance ?
Last Answer : Free energy (or Helmholtz function) is defined as/= u -Ts. It is equal to the work during a constant-volume isothermal reversible nonflow process. Free enthalpy (or Gibbs function) is ... for reversible constant-pressure isothermal nonflow processes, change in free energy is equal to net work.
Last Answer : Free energy (or Helmholtz function) is defined as/= u -Ts. It is equal to the work during a constant-volume isothermal reversible nonflow process. Free enthalpy (or Gibbs function) is ... or for reversible constant-pressure isothermal nonflow processes, change in free energy is equal to net work.
Description : What are the names given to constant temperature, constant pressure, constant volume, constant internal energy, constant enthalpy, and constant entropy processes.
Last Answer : Isothermal, isochroic, isobaric, free expression, throttling and adiabatic processes respectively.
Description : Mollier chart is a __________ plot. (A) Pressure vs. enthalpy (B) Pressure vs. volume (C) Enthalpy vs. entropy (D) Temperature vs. entropy
Last Answer : (C) Enthalpy vs. entropy
Description : 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
Last Answer : Mollier diagram
Description : An ideal gas is compresses isothermally. The enthalpy change is a. Always negative b. Always positive c. zero d. undefined
Last Answer : zero
Description : Which of the following occurs in a reversible polytrophic process? a. Enthalpy remains constant b. Internal energy does not change c. Some heat transfer occurs d. Entropy remains constant
Last Answer : Some heat transfer occurs
Description : What happens to the internal energy of water at reference temperature where enthalpy is zero? a. Becomes negative b. Becomes positive c. Remains constant d. Cannot be defined
Last Answer : Becomes negative
Description : 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 ... of products. d. The enthalpy of the product is lower than the enthalpy of the reactant
Last Answer : the enthalpy of reactants is lower than the enthalpy of products.
Description : 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
Description : A state occurs in isentropic process a. The change in entropy is 0 b. The change in entropy is 1 c. The change in enthalpy is 0 d. The change in enthalpy is 1
Last Answer : The change in entropy is 0
Description : Regardless of the process, the change in enthalpy firm moles of ideal gas is a. Heat b. Enthalpy c. Entropy d. Density
Last Answer : Heat
Description : The 1st Law of Thermodynamics on what principle? a. Conservation of Energy b. Conservation of mass c. Enthalpy d. Isometric
Last Answer : Conservation of Energy
Description : Gas being heated at constant volume is undergoing the process of. a. isometric b. specific heat c. enthalpy d. isothermal
Last Answer : isometric
Description : Composite property applicable to all fluids a. Entropy b. Enthalpy c. Specific Heat d. None of the above