Description : The efficiency of a Carnot heat engine operating between absolute temperatures T1 and T2 (when, T1 > T2) is given by (T1- T2)/T1. The co efficient of performance (C.O.P.) of a Carnot heat pump operating between T1 and T2is given by (A) T1/(T1-T2) (B) T2/(T1-T2) (C) T1/T2 (D) T2/R1
Last Answer : (A) T1/(T1-T2)
Description : The efficiency of a Carnot heat engine operating between absolute temperatures T1 and T2(when, T1 > T2) is given by (T1- T2)/T1. The co efficient of performance (CO.P.) of a Carnot heat pump operating between T1 and T2is given by (A) T1/(T1-T2) (B) T2/(T1-T2) (C) T1/T2 (D) T2/T1
Last Answer : (B) T2/(T1-T2)
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 : 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 : The heat supplied to the gaS at constant volume is (where m = Mass of gas, cv = Specific heat at constant volume, cp = Specific heat at constant pressure, T2 – T1 = Rise in temperature, and R = Gas constant) A. mR(T2 – T1) B. mcv(T2 – T1) C. mcp(T2 – T1) D. mcp(T2 + T1)
Last Answer : Answer: B
Description : An engine operates between temperatures of 900°Kandr2 and another engine between T2 and 400°K For both to do equal work, value of T2 will be (a) 650°K (b) 600°K (c) 625°K (d) 700°K (e) 750°K.
Last Answer : Answer : a
Description : Assuming compression is according to the Law PV = C, Calculate the initial volume of the gas at a pressure of 2 bars w/c will occupy a volume of 6m³ when it is compressed to a pressure of 42 Bars. a) 130m³ b) 136m³ c) 120m³ d) 126m³ Formula: P1V1/T1 =P2V2/T2
Last Answer : 126m³
Description : The pressure gauge on a 2000 m³ tank of oxygen gas reads 600 kPa. How much volumes will the oxygen occupied at pressure of the outside air 100 kPa? a) 14026.5 m³ b) 15026.5 m³ c) 13026.5 m³ d) 16026.5 m³ Formula: P1V1/T1 =P2V2/T2
Last Answer : 14026.5 m³
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 : 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 : 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 : Which of the following is the mathematical representation of the Charles’s law? A. V1/V2= P2/P1 B. V1/T1=V2/T2 C. V1/T2=V2/T1 D. V1/V2=√P2/√P1
Last Answer : V1/T1=V2/T2
Description : Which of the following is the Ideal gas law (equation)? A. V/T = K B. V= k*(1/P) C. P1/T1 = P2/T2 D. PV = nRT
Last Answer : PV = nRT
Description : Efficiency of a Carnot engine working between temperatures T1 and T2(T1 < T) is (A) (T2- T1)/T2 (B) (T2- T1)/T1 (C) (T1- T2)/T2 (D) (T1- T2)/T1
Last Answer : (A) (T2- T1)/T2
Description : The efficiency of a Carnot engine depends on (a) working substance (b) design of engine (c) size of engine (d) type of fuel fired (e) temperatures of source and sink.
Last Answer : Answer : e
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 : 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.
Last Answer : Answer : d
Description : The efficiency of Carnot cycle is maximum for (a) gas engine (b) well lubricated engine (c) petrol engine (d) steam engine (e) reversible engine.
Description : Carnot cycle has maximum efficiency for (a) reversible engine (b) irreversible engine (c) new engine (d) petrol engine (e) diesel engine.
Description : What is the value of maximum COP in case of absorption refrigeration, if refrigeration provided is at temperature, TR (where, T1 and T2 are source & surrounding temperatures respectively.)? (A) TR/(T2 - TR) (T1 - T2 )/T1 (B) TR ... T1 /(T1 - T2 ) (C) TR/(T1 - TR) (T1 - T2 )/T1 (D) None of these
Last Answer : (A) TR/(T2 - TR) × (T1 - T2 )/T1
Description : What states that thermal efficiencies of all reversible heat engines operating between the same two reservoirs are the same and that no heat engine is more efficient than a reversible one operating between the ... A. Ericson principle B. Carnot principle C. Otto principle D. Stirling principle
Last Answer : Carnot principle
Description : Otto cycle efficiency is higher than Diesel cycle efficiency for the same compression ratio and heat input because in Otto cycle A. combustion is at constant volume B. expansion and compression are isentropic C. maximum temperature is higher D. heat rejection is lower
Last Answer : Answer: D
Description : What predicts the approximate molar specific heat at high temperatures from the atomic weight? A. Third law of thermodynamics B. Law of Dulong and Petit C. Mollier diagram D. Pressure-enthalpy diagram
Last Answer : Law of Dulong and Petit
Description : Which law states that the specific heat of a gas remains constant at all temperatures and pressures (a) Charles’ Law (b) Joule’s Law (c) Regnault’s Law (d) Boyle’s Law (e) there is no such law.
Last Answer : Answer : c
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 : 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 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 : A simple steam engine receives steam from the boiler at 180˚C and exhausts directly into the air at 100˚C. What is the upper limit of its efficiency? a. 11.28 % b. 36.77 % c. 20.36 % d. 17.66 %
Last Answer : 17.66 %
Description : An actual engine is to be designed having same efficiency as the Carnot cycle. Such a proposition is (a) feasible (b) impossible (c) possible (d) possible, but with lot of sophistications (e) desirable.
Description : Carnot cycle efficiency depends upon (a) properties of the medium/substance used (b) condition of engine (c) working condition (d) temperature range of operation (e) effectiveness of insulating material around the engine.
Description : The more effective way of increasing efficiency of Carnot engine is to (a) increase higher temperature (b) decrease higher temperature (c) increase lower temperature (d) decrease lower temperature (e) keep lower temperature constant.
Description : The ratio of equilibrium constants (Kp2/Kp1) at two different temperatures is given by (A) (R/∆H) (1/T1- 1/T2) (B) (∆H/R) (1/T1- 1/T2) (C) (∆H/R) (1/T2- 1/T1) (D) (1/R) (1/T1- 1/T2)
Last Answer : (B) (∆H/R) (1/T1- 1/T2)
Description : The equilibrium constant for a chemical reaction at two different temperatures is given by (A) Kp2/Kp1 = - (∆H/R) (1/T2- 1/T1) (B) Kp2/Kp1 = (∆H/R) (1/T2- 1/T1) (C) Kp2/Kp1 = ∆H (1/T2- 1/T1) (D) Kp2/Kp1 = - (1/R) (1/T2- 1/T1)
Last Answer : (A) Kp2/Kp1 = - (∆H/R) (1/T2- 1/T1)
Description : Co-efficient of performance for a reversed Carnot cycle working between temperatures T1 and T2(T1 > T2) is (A) T2/(T1- T2) (B) T1/(T1- T2) (C) (T1- T2)/T1 (D) (T1- T2)/T2
Last Answer : (A) T2/(T1- T2)
Description : The most efficient heat engine that can operate between two temperature reservoirs T1 and T2 is: w) jet engine x) internal combustion engine y) Carnot engine (pron: car-no) z) steam engine
Last Answer : ANSWER: Y -- CARNOT ENGINE
Description : What refers to the amount of heat removed from the cooled space in BTS’s for 1 watt-hour of electricity consumed? A. Cost efficiency rating B. Energy efficiency rating C. Coefficient of performance D. Cost of performance
Last Answer : Energy efficiency rating
Description : What is the ratio of the useful heat extracted to heating value? A. Combustion efficiency B. Phase efficiency C. Heat efficiency D. Work efficiency
Last Answer : Combustion efficiency
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 : For same compression ratio and for same heat added (a) Otto cycle is more efficient than Diesel cycle (b) Diesel cycle is more efficient than Otto cycle (c) efficiency depends on other factors (d) both Otto and Diesel cycles are equally efficient (e) none of the above.
Description : Which of the following cycles has maximum efficiency (a) Rankine (b) Stirling (c) Carnot (d) Brayton (e) Joule.
Description : Carnot cycle efficiency is maximum when (a) initial temperature is 0°K (b) final temperature is 0°K (c) difference between initial and final temperature is 0°K (d) final temperature is 0°C (e) initial temperature is minimum possible.
Last Answer : Answer : b
Description : At same temperatures, the radiation emitted by all real surfaces is ______ the radiation emitted by a black body. A. Less than B. Greater than C. Equal to D. Either less than or greater than
Last Answer : Less than
Description : The temperatures of the ideal gas temperature scale are measured by using a ______. A. Constant-volume gas thermometer B. Constant-mass gas thermometer C. Constant-temperature gas thermometer D. Constant-pressure gas thermometer
Last Answer : Constant-volume gas thermometer
Description : What law states that it is impossible to operate an engine operating in a cycle that will have no other effect than to extract heat from a reservoir and turn it into an equivalent amount of work? ... B. First law of thermodynamics C. Second law of thermodynamics D. Third law of thermodynamics
Last Answer : Second law of thermodynamics
Description : 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
Last Answer : Thermal pump
Description : Is a thermodynamic system that operates continuously with only energy (heat and work) crossing its boundaries? a. Heat Engine b. Heat Reservoir c. Heat Source d. Heat Sink
Last Answer : Heat Engine