Description : What is the emissivity of a black body? A. 0 B. 1 C. 0.5 D. 0.25
Last Answer : 1
Description : What refers to the rate of thermal radiation emitter per unit area of a body? A. Thermal conductivity B. Absorptivity C. Emissivity D. Emissive power
Last Answer : Emissive power
Description : 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
Last Answer : Compressibility factor
Description : Which is NOT a characteristic of emissivity? A. It is high with most nonmetals B. It is directly proportional to temperature C. It is independent with the surface condition of the material D. It is low with highly polished metals
Last Answer : It is independent with the surface condition of the material
Description : While swimming at depth of120m in a fresh water lake, A fish emits an air bubbles of volume 2.0mm³ atmospheric pressure is 100kPa. What is the pressure of the bubble? a) 217.7 kPa b) 317.7 kPa c) 417.7 kPa d) 517.7 kPa Formula: P= δh
Last Answer : 217.7 kPa
Description : While swimming a depth of 13m in a fresh water lake a fish emits an air bubble of volume 2 mm² atmospheric pressure is 100kpa what is the original pressure of the bubble. a. 217.17 kpa b. 119 kpa c. 326.15 kpa d. 210 kap Pabs = Pg + Patm
Last Answer : 217.17 kpa
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 : It is a process during which the pressure remains constant a. Adiabatic b. Isentropic c. Isobaric d. Isotropic
Last Answer : Isobaric
Description : 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
Last Answer : Charles’ Law
Description : An ideal gas is compressed in a cylinder so well insulated that there is essentially no heat transfer. The temperature of gas a. Remains constant b. increases c. decreases d. is basically zero
Last Answer : increases
Description : As temperature goes to “0”, the entropy approaches a constant a. Zeroth Law of Thermodynamics b. First Law of Thermodynamics c. Second Law of Thermodynamics d. Third Law of Thermodynamics
Last Answer : Third Law of Thermodynamics
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 : 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
Last Answer : Boyle’s Law
Description : Is a steady flow process at total constant pressure through a control volume for which there is no heat? a. Adiabatic Saturation Process b. Dew point c. Adiabatic Ratio d. None of the above
Last Answer : Adiabatic Saturation Process
Description : The volume of a confined gas is held constant, the pressure is directly proportional to the absolute temperature. a. Charle’s Law b. Boyle’s Law c. Joule’s Law d. Specific Heat
Description : The pressure of the confined gas is held constant, the volume directly proportional to the absolute temperature. a. Charle’s Law b. Boyle’s Law c. Zeroth Law d. Gas Law
Last Answer : Charle’s Law
Description : The gas constant is equal to a. Cp – Cv b. Cp + Cv c. Cp – Cv + k d. None of the above
Last Answer : Cp – Cv
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 : _____ is that property of a substance which remains constant if no heat enters or leaves the substance, while it does work or alters its volume, but which increases or diminishes should a small amount of heat enter or leave. a. Entrophy b. Enthalpy c. Specific Heat d. None of the above
Last Answer : Entrophy
Description : Heat cannot be created, nor destroyed, but it can be changed from one form to another. The energy in the universe remains constant. a. 1st Law of Energy Conservation b. 2nd Law of Energy Conservation c. 3rd Law of Energy Conservation d. None of the above
Last Answer : 1st Law of Energy Conservation
Description : “If the temperature o f a fixed quantity of a gas is held constant during a change of state, the volume varies inversely with the absolute pressure. a. Charle’s Law b. Boyle’s Law c. Dalton’s Law d. Amagat’s Law
Description : A certain gas, with cp = 0.529Btu/ lb. °Rand R = 96.2ft.lb/lb. °R, expands from 5 cu ft and 80°F to 15 cu ft while the pressure remains constant at 15.5psia. Compute for T2. a.1520°R b. 1620°R c. 1720°R d. 1820°R formula: T2= T1V2/V1
Last Answer : 1620°R
Description : A perfect gas has a value of R= 319.2 J/ kf.K and k= 1.26. If 120 kJ are added to 2.27 kf\g of this gas at constant pressure when the initial temp is 32.2°C? Find T2. a. 339.4 K b. 449.4 K c. 559.4K d. 669.4K formula: cp = kR/ k-1 Q= mcp(T2-T1)
Last Answer : 339.4 K
Description : Ten cu. ft of air at 300psia and 400°F is cooled to 140°F at constant volume. What is the transferred heat? a.-120Btu b. -220Btu c.-320Btu d. -420Btu formula: Q= mcv(T2-T1)
Last Answer : -420Btu
Description : A gas having a volume of100 ft³ at 27ºC is expanded to 120 ft³by heated at constant pressure to what temperature has it been heated to have this new volume? a. 87°C b. 85°C c. 76°C d. 97°C t2= T2–T1
Last Answer : 87°C
Description : A certain gas with cp = 0.529Btu/lb°R and R = 96.2ft/lbºR expands from 5 ft and 80ºF to 15 ft while the pressure remains constant at 15.5 psia. a. T2=1.620ºR, ∫H = 122.83 Btu b. T2 = 2°R, ∫H = 122.83 Btu c. ... , ∫H = 122.83 Btu d. T2 = 1°R, ∫H = 122.83 Btu T2= V2(t2)/V1 and ∫H = mcp (T2-T1)
Last Answer : T2=1.620ºR, ∫H = 122.83 Btu
Description : The volume of the gas held at constant pressure increases 4 cm² at 0°C to 5cm². What is the final pressure? a. 68.65ºC b. 68.25ºC c. 70.01°C d. 79.1ºC t2= T2–T1
Last Answer : 981 N
Description : An ideal gas at 45psig and 80ºF is heated in the close container to 130ºF. What is the final pressure? a. 65.10 psi b. 65.11 psi c. 65.23 psi d. 61.16 psi P1V1/T1= P2V2/T2;V = Constant
Last Answer : 65.23 psi
Description : A certain gas, with cp = 0.529Btu/lb.°R and R = 96.2 ft.lb/lb.°R, expands from 5 cu ft and 80°F to 15 cu ft while the pressure remains constant at 15.5 psia. Compute for T2. (Formula: T2= T1V2/V1) a. 460°R b. 270°R c. 1620 °R d. None of the above
Last Answer : 1620 °R
Description : There are 1.36 kg of gas, for which R = 377 J/kg.k and k = 1.25, that undergo a nonflow constant volume process from p1 = 551.6 kPa and t1 = 60°C to p2 = 1655 kPa. During the process the gas is internally stirred and ... (Formula: T2= T1p2/ p1) a. 999 K b. 888 K c. 456 K d. One of the above
Last Answer : 999 K
Description : Ten cu ft. of air at 300 psia 400°F is cooled to 140°F at constant volume. What is the final pressure? (formula: p2 = p1T2/T1) a. 0 b. 209 psia c. - 420 psia d. None of the above
Last Answer : 209 psia
Description : Gas is enclosed in a cylinder with a weighted piston as the stop boundary. The gas is heated and expands from a volume of 0.04 m^3 to 0.10 m^3 at a constant pressure of 200kPa.Calculate the work done by the system. A. 8 kJ B. 10 kJ C.12 kJ D.14 kJ Formula: W = p(V2-V1)
Last Answer : 12 kJ
Description : Twenty grams of oxygen gas are compressed at a constant temperature of 30 ˚C to 5%of their original volume. What work is done on the system. A.824 cal B.924 cal C.944 cal D.1124 cal Formula: W = -mRTln (V2/V1) Where R = (1.98 cal/gmole·K) (32 g/gmole)
Last Answer : 1124 cal
Description : What is the equation for the work done by a constant temperature system? A. W = mRTln(V2-V1) B. W = mR( T2-T1 ) ln( V2/V1) C. W = mRTln (V2/V1) D. W = RT ln (V2/V1) Formula : W=∫ pdV lim1,2 ∫ = mRT / V
Last Answer : W = mRTln (V2/V1)
Description : What is the resulting pressure when one pound of air at 15 psia and 200 ˚F is heated at constant volume to 800 ˚F? A.15 psia B. 28.6 psia C. 36.4 psia. D. 52.1 psia Formula : T1/p1 = T2/p2 p2= p1T2 / T1
Last Answer : 28.6 psia
Description : From the steam table, determine the average constant pressure specific heat (c) of steam at 10 kPa and45.8 ˚C A.1.79 kJ/ kg-˚C B.10.28 kJ/ kg-˚C C.30.57 kJ/ kg-˚C D. 100.1 kJ/ kg-˚C Formula: h = c T ∆ ∆ From the steam table At 47.7 ˚C h= 2588.1 kJ/ kg At 43.8 ˚C h= 2581.1 kJ/ kg
Last Answer : 1.79 kJ/ kg-˚C
Description : The compressibility factor, x, is used for predicting the behavior of nonideal gases. How is the compressibility ty factor defined relative to an ideal gas? (subscript c refers to critical value) A. ... compressibility factor, x, is an dimensionless constant given by pV=zRT. Therefore z = pV / RT
Last Answer : z = pV/ RT
Description : The most efficient cycle that can operate between two constant temperature reservoir is the _________. a. Otto Cycle b. Lazare Cycle c. Isothermal Cycle d. Carnot Cycle
Last Answer : Carnot Cycle
Description : The flow through an open system is _________ if all properties at each point within the system remain constant with respect to time. a. streamline flow b. steady flow c. constant flow d. algebraic flow
Last Answer : steady flow
Description : A gas is enclosed in a cylinder with a weighted piston as the top boundary. The gas is heated and expands from a volume of 0.04 m3 to 0.10 m3 at a constant pressure of 200 kPa. Find the work done on the system. a. 5 kJ b. 15 kJ c. 10 kJ d. 12 kJ
Description : _________ is the temperature to which the air must be cooled, at constant pressure, to produce saturation. a. relative humidity b. triple point temperature c. dew point d. critical point
Last Answer : dew point
Description : An ideal gas is maintained at constant temperature. If the pressure on the gas is doubled, the volume is a. increased fourfold b. doubled c. reduced by half d. decreased by a quarter
Last Answer : reduced by half
Description : As we heat a gas at constant pressure, its volume a. increases b. decreases c. stays the same d. none of the above
Description : On a day when the partial pressure of water vapor remains constant, what happens as the temperature rises? a. the relative humidity increases b. the relative humidity decreases c. the relative humidity remains constant d. the air would eventually become saturated
Last Answer : the relative humidity decreases
Description : The gas in a constant gas thermometer cooled to absolute zero would have _________. a. no volume b. no pressure c. zero temperature at all scales d. none of the above
Last Answer : no pressure
Description : The volume of a given amount of water _________ as the temperature decreases from 4˚C to 0˚C. a. decreases b. increases c. remains constant d. none of the above
Description : An ideal gas whose specific heats are constant is called _____. A. Perfect gas B. Natural gas C. Artificial gas D. Refined gas
Last Answer : Perfect gas
Description : “At constant pressure, the volume of a gas is inversely proportional to the pressure”. This is known as ______. A. Boyle’s Law B. Charles’s Law C. Gay-Lussac Law D. Ideal gas law
Description : A process during which entropy remains constant is called ______ process A. Isometric B. Isochoric C. Isobaric D. Isentropic
Last Answer : Isentropic