1. Steam with an enthalpy of 800 kcal/kg enters a nozzle at a velocity of 80 m/s.

Find the velocity of the

steam at the exit of the nozzle if its enthalpy is reduced to 750 kcal/kg, assuming the nozzle is horizontal
and disregarding heat losses. Take g = 9.81 m/s2 and J constant = 427 kg m/kcal.
A. 452.37 m/s C. 651.92 m/s
B. 245.45 m/s D. 427.54 m/s

2. Steam is expanded through a nozzle and the enthalpy drop per kg of steam from the initial pressure to the
final pressure is 60 kJ. Neglecting friction, find the velocity of discharge and the exit area of the nozzle to
pass 0.20 kg/s if the specific volume of the steam at exit is 1.5 m 3 /kg.
A. 346.4 m/s, 879 m2 C. 765.6 m/s, 467 m2
B. 356.7 m/s, 278 m2 D. 346.4 m/s, 866 m2
3. A 6 MW steam turbine generator power plant has a full-load steam rate of 8 kg/kW-hr. Assuming that no-
load steam consumption as 15% of full-load steam consumption, compute for the hourly steam consumption
at 75% load, in kg/hr.
A. 37,800 kg/hr C. 30,780 kg/hr
B. 38,700 kg/hr D. 30,870 kg/hr

4. A 4 kg of air enters a turbine with enthalpy of 600 kJ and velocity of 250 m/s. The enthalpy at exit is 486
kJ and velocity of 170 m/s. What is the work developed if there is a heat loss of 10 kJ?
A.128.83 kJ C. 80.2 kJ
B.171.2 kJ D. 28.3 kJ

5. Calculate drive horsepower for pumping 1703 L/min cold water to a tank suction at 127 mm Hg vacuum,
delivery at 5.3 kg/cm2 ga., both measured close to pump, ep = 0.65.
A. 31.42 HP C. 35.42 HP
B. 20.42 HP D. 23.02 HP

6. Find the length of a suspension bunker to contain 181 tons of coal without surcharge; width 4.6 m; depth
4.3 m. The level capacity of a suspension bunker is 5/8 wdl where: w = width, d = depth, l = length. Density
of coal, 800 kg/m3.
A.18.30 m C. 17.61 m
B. 13.80 m D. 12.61 m

7. A 305 mm x 457 mm four stroke single acting diesel engine is rated at 150 kW at 260 rpm. Fuel
consumption at rated load is 0.26 kg/kW-hr with a heating value of 43,912 kJ/kg. Calculate the brake
thermal efficiency.
A. 31.63 % C. 21.63 %
B. 41.63 % D. 35.63 %

8. The brake thermal efficiency of a 1 MW diesel electric plant is 36 %. Find the heat generated by fuel in
kW if the generator efficiency is 89 %.
A. 3,121.10 kW C. 4,121.10 kW
B. 3,528.64 kW D. 4,528.64 kW

9. In an air–standard Brayton cycle, compressor receives air at 101.325 kPa, 21 ˚ C and leaves at 600 kPa at
the rate of 4 kg/s. Determine the turbine work if the temperature of the air entering the turbine is 1000 ˚ C.
A. 3000 kW C. 2028 kW
B. 2701 kW D. 3500 kW

10. Kerosene is the fuel of a gas turbine plant: fuel – air ratio, m f = 0.012, T3 = 942 K, pressure ratio, rp = 4.5,
exhaust to atmosphere. Find the available energy in kJ per kg air flow. Assume k = 1.34 and C p = 1.13.
A. 352.64 kJ/kg C. 252.64 kJ/kg
B. 452.64 kJ/kg D. 552.64 kJ/kg
11. An ideal gas turbine operates with a pressure ratio of 10 and the energy input in the high temperature
heat exchanger is 300 kW. Calculate the air flow rate for a temperature limit of 30 ˚ C and 1200˚ C.
A. 0.25 kg/s ` C. 0.41 kg/s
B. 0.34 kg/s D. 0.51 kg/s

12. In an air-standard Brayton cycle the inlet temperature and pressure are 20 ˚ C and 101.325 kPa. The
turbine inlet conditions are 1200 kPa and 900˚ C. Determine the air flow rate if the turbine produces 12 MW.
A. 21.41 kg/s C. 19.25 kg/s
B. 20.20 kg/s D. 18.10 kg/s

13. A gas turbine power plant operating on the Brayton cycle delivers 15 MW to a standby electric
generator. What is the mass flow rate and the volume flow rate of air if the minimum and maximum
pressures are 100 kPa and 500 kPa respectively and temperature of 20˚ C and 1000˚ C.
A. 31.97 kg/s, 26.88 m3/s C. 41.97 kg/s, 26.88 m3/s
B. 36.98 kg/s, 28.99 m /s
3
D. 46.98 kg/s, 28.99 m3/s

14. In a hydraulic plant the difference in elevation between the surface of the water at intake and the
tailrace is 650 ft when the flow is 90 cfs, the friction loss in the penstock is 65 ft and the head utilized by the
turbine is 500 ft. The mechanical friction in the turbine is 110 Hp and the leakage loss is 4 cfs. Find the
hydraulic efficiency.
A. 87.45 % C. 85.47 %
B. 84.57 % D. 78.54 %

15. A hydro-electric power plant consumes 60,000,000 kW-hr per year. What is the net head if the expected
flow is 1500 m3/min and over-all efficiency is 63%?
A. 34.34 m C. 44.33 m
B. 43.43 m D. 33.44 m

16. A Pelton type turbine has a gross head of 40 m and a friction head loss of 6 m. What is the penstock
diameter if the penstock length is 90 m and the coefficient of friction head loss is 0.001 (Morse).
A. 2040 mm C. 2440 mm
B. 3120 mm D. 2320 mm

17. The water velocity of a 5 m x 1 m channel is 6 m/s. What is the annual energy produced if the net head
is 120 m and the over-all efficiency is 80 %?
A. 494, 247, 258 kW-hrs. C. 247, 494, 528 kW-hrs.
B. 247, 497, 582 kW-hrs. D. 472, 497, 582 kW-hrs.

18. A hydro-electric impulse turbine is directly coupled to a 24 pole, 60 Hz alternator. It has a specific speed
of 60 rpm and develops 3000 Hp. What is the required diameter assuming a peripheral speed ratio of 0.45?
A. 0.661 m C. 0.443 m
B. 0.552 m D. 0.775 m

19. In a hydroelectric power plant the tail water elevation is at 500 m. What is the head water elevation if
the net head is 30 m and the head loss is 5% of the gross head?
A. 785.25 m C. 528.57 m
B. 582.57 m D. 758.25 m

20. The tailwater and the headwater of a hydro-electric power plant are 150 m and 200 m respectively. What
is the water power if the flow is 15 m3/s and a head loss of 10% of the gross head?
A. 6,621.75 kW C. 5,621.76 kW
B. 7,621.65 kW D. 4,621.56 kW
21. In a hydroelectric power plant, water flows at 10 m/s in a penstock of 1 m 2 cross-sectional area. If the
net head of the plant is 30 m and the turbine efficiency is 85%, what is the turbine output?
A. 2,501.55 kW C. 3,626.34 kW
B. 2,100.21 kW D. 3,124.65 kW

22. A 75 MW power plant has an average load of 35,000 kW and a load factor of 65%. Find the reserve
over peak.
A. 21.15 MW C. 25.38 MW
B. 23.41 MW D. 18.75 MW

23. A power plant is said to have/had a use factor of 48.5% and a capacity factor of 42.4%. How many
hours did it operate during the year?
A. 6,600.32 hrs. C. 8,600.32 hrs.
B. 7,658.23 hrs. D. 5,658.23 hrs.

24. A 50,000 kW steam plant delivers an annual output of 238,000,000 kW-hr with a peak load of 42,860
kW. What is the annual load factor and capacity factor?
A. 0.634, 0.534 C. 0.634, 0.543
B. 0.643, 0.534 D. 0.643, 0.543

25. Calculate the use factor of a power plant if the capacity factor is 35 % and it operates 8000 hrs. during
the year?
A. 38.325 % C. 35.823 %
B. 33.825 % D. 32.538 %

26. If the air required for combustion is 20 kg per kg of coal and the boiler uses 3000 kg of coal per hr.,
determine the mass of gas entering the chimney. Assume an ash loss of 15 %.
A. 40,644 kg/hr. C. 62,550 kg/hr.
B. 70,200 kg/hr. D. 50,000 kg/hr.

27. A 15 kg gas enters a chimney at 10 m/s. If the temperature and pressure of a gas are 26°C and 100 kPa
respectively, what is the diameter of the chimney? Use R=0.287 kJ/kg-K.
A. 1.57 m C. 2.22 m
B. 2.65 m D. 1.28 m

28. A two-stage air compressor at 90 kPa and 20°C discharge at 700 kPa. Find the polytropic exponent if the
intercooler intake temperature is 100°C.
A. 1.29 C. 1.4
B. 1.33 D. 1.25

30. A two stage compressor receives 0.35 kg/s of air at 100 kPa and 269 K and delivers it at 5000 kPa. Find
the heat transferred in the intercooler.
A. 70.49 kW C. 90.49 kW
B. 80.49 kW D. 100.49 kW

31. A centrifugal pump discharged 20 L/s against a head of 17 m when the speed is 1500 rpm. The diameter
of the impeller was 30 cm and the brake horsepower was 6.0Hp geometrically similar pump 40 cm in
diameter is to run at 1750 rpm. Assuming equal efficiencies, what brake horsepower is required?
A. 51.55 Hp C. 40.14 Hp
B. 50.15 Hp D. 45.15 Hp
32. A pump delivers 20 cfm of water having a density of 62 lb/ft 3. The suction and discharge gage reads 5 in
Hg vacuum and 30 psi respectively. The discharge gage is 5 ft above the suction gage. If pump efficiency is
70%, what is the motor power?
A. 5.31 Hp C. 4.31 Hp
B. 3.31 Hp D. 6.31 Hp

33. Calculate the air power of a fan that delivers 1200 m 3/min of air through a 1 m by 1.5 m outlet. Static
pressure is 120 mm WG and density of air is 1.18.
A. 20.45 kW C. 30.45 kW
B. 25.64 kW D. 35.64 kW

34. Determine the temperature for which a thermometer with degrees Fahrenheit is numerically twice the
reading of the temperature in degrees Celsius.
A. -24.6 B. 320 C. 160 D. -12.3

35. During takeoff in a spaceship, an astronaut is subjected to acceleration equal to 5 times the pull of the
earth's standard gravity. If the astronaut is 180 lbm and the takeoff is vertical, what force does he exert on the
seat?
A. 4810.9 N B. 4414.5 N C. 8829 N D. 9620 N

36. A pressure cooker operates by cooking food at higher pressure and temperature than is possible at
atmospheric conditions. Steam is contained in the seal pot, with vent hole in the middle of the cover,
allowing steam to escape. The pressure is regulated by covering the vent hole with a small weight, which is
displaced slightly by escaping steam. Atmospheric pressure is 100 kPa, the vent hole area is 7 mm 2, and the
pressure inside should be 200 kPa. What is the mass of the weight?
A. 0.107 kg B. 1.05 kg C. 1.75 kg D. 0.1783 kg

37. A barometer can be used to measure an airplane's altitude by comparing the barometric pressure at a
given flying altitude to that on the ground. Determine an airplane's altitude if the pilot measures the
barometric pressure at 700 mmHg, the ground is at 758 mmHg and the average air density is 1.19 kg/m 3.
g = 9.8 m/s2
A. 987m B. 633m C. 788m D. 663m

38. A mixture of 0.4 lbm of helium and 0.2 lbm of oxygen is compressed polytropically from 14.7 psia
and 60˚F to 60 psia according to n = 1.4. Determine the final temperature, T2
A. 727.7˚R B. 777.2˚R C. 722.7˚R D. 277.7˚R

39. A mixture of 0.4 lbm of helium and 0.2 lbm of oxygen iscompressed polytropically from 14.7 psia and
60˚F to 60 psia according to n = 1.4. Determine the polytropic work.
A. 139 Btu B. 239 Btu C. 339 Btu D. 539 Btu

40. A pump in a municipality's water-supply system recieves water from the filtration beds and pumps it up
to the top of a water tower. The tower's height is 3 5m and the inlet piping to the pump is 12 m below the
pump's intake. The water mass flow rate through the pump is 100 kg/s, the diameter of the inlet piping is 25
cm and the diameter of the discharge piping is 15 cm. Determine the power required by the pump.
A. 77.3 kW B. 33.77 kW C. 34.42 kW D. 42.34 kW

41. An adiabatic tank containing air is used to power an air turbine during times of peak power demand. The
tank has a volume of 500 m3 and contains air at 1000 kPa and 500˚K. Determine the mass remaining the
pressure reaches 100 kPa.
A. 276.37 kg B. 672.73 kg C. 772.73 kg D. 227.73 kg

42. Determine the air-fuel ratio on a molar basis for the complete combustion of octane with theoretical
amount of air.
A. 59.5 kgair / kgfuel
43. During a steady state operation, a gearbox recieves 60 kW through the input shaft and delivers power
through the output shaft. For the gearbox as the system, the rate of energy transfer is by convection. h =
0.171 kW/m2-K is the heat transfer coefficient, A = 1.0 m 2 is the outer surface area of the gearbox, Th =
300˚K (27˚C) is the temperature is the outer surface, T f = 293˚K (20˚C) is the temperature of the
surroundings away from the immediate vicinity of the gearbox. Determine the power delivered to the output
shaft in kW if the heat transfer rate is -1.2 kW.
A. 98.8 kW B. 78.8 kW C. 68.8 kW D. 58.8 kW

44. A single acting air compressor with a clearance of 6% takes in air at atmospheric pressure and
temperature of 85˚F, and discharges it at a pressure of 85 psia. The air handled is 0.25 ft 3 / cycle measured at
discharge pressure. If the compression is isentropic, find the piston displacement per cycle, if the
compressor is running at 750 rpm.
A. 0.0750 ft3 / cycle B. 0.025 ft3 / cycle C.1.030 ft3 / cycle D. 1.090 ft3 / cycle

45. A single acting air compressor with a clearance of 6% takes in air at atmospheric pressure and
temperature of 85˚F and discharges it at a pressure of 85 psia. The air handled is 0.25 ft 3 / cycle measyred at
discharge. If the compression is isentropic, find the air hp of the compressor if rpm is 750.
A. 16 hp B. 96 hp C. 69 hp D. 61 hp

46. A nozzle receives 0.5 kg /s of air at a pressure 0f 2700 kPa and a velocity 0f 30 m/s and with an enthalpy
of 923 kJ/kg, and the air leaves at a pressure of 700 kPa and with an enthalpy of 660 kJ/kg. Determine the
exit velocity from the nozzle.
A. 923 m / s B. 726 m /s C. 700 m / s D. 660 m / s

47. A two stage, double acting compressor is to deliver 90 lb / min of air from 14.3 psia and 90˚F to a final
pressure of 185 psia. The normal barometer is 29.8 inHg and the temperature is 80˚F. The pressure drop in
the intercooler is 3 psia and the speed is 210 rpm and pV1.34 = C during compression and expansion. The
clearance is 5% for both cylinders. The temperature of the cooling water increases by 18˚F. find the volume
of free air.
A. 1282 CFM B. 1230 CFM C. 1320 CFM D. 1822 CFM

48. Consider 4800 lb of steam per hour flowing through a pipe at 100 psia pressure. Assume a velocity of
5280 ft / min. What size of pipe is required? Specific volume of steam at 100 psia v = 4.432 ft 3 / lb.
A. 3 in B. 5 in C. 4 in D. 6 in

49. A boiler plant generates 225,000 lbof steam and burn 13.9 tons of coal per hour. The coal has a heating
value of 11,400 Btu / lb A test of the particulate leaving the boiler shows that 3804 lb of particulate is being
discharged per hour. What is the particulate discharged per million Btu heat input to the furnace?
A. 12 lb / 106 Btu B. 14 lb / 106 Btu C. 15 lb / 106 Btu D. 16 lb / 106 Btu

50. A turbine recieves 150 lbm / sec of air at 63 psia and 2450˚R and expands it polytropically to 14.7 psia.
The exponent n is equal to 1.45 for the process. Determine the power.
A. 52,343.16 Btu / sec B. 53,343.16 kW
C. 53,343.16 hp D. 53,343.16 ft-lb / sec

51. Find the thrust and efficiency of two 2 m diameter propellers through which flows a total of 600 m 3 / sec
of air 11.3 N / m3. The propellers are attached to an airplane moving at 250 kph through still air. Neglect
eddy losses.
A. 36,077 N, 73% B. 77,630 N, 37% C. 66,033 N, 33% D. 77,330 N, 77%

52. A liquid with a specific gravity of 1.26 is being pumped in a pipeline from A to B. At A, the pipe
diameter is 60 cm and the pressure is 300 kN / m 2. At B, the pipe diameter is 30 cm and the pressure is 330
kN / m2. Point B is 1.0 m lower than A. Find the flow rate if the pump puts 16 kW into the flow. Neglect
head loss.
A. 4.2 m3 / s B. 0.42 m3 / s C. 2.4 m3 / s D. 0.24 m3 / s
53. A reciprocating compressor handles 1,400 cfm of air measured at intake where p 1 = 18 psia and t1 =
90˚F. The discharge pressure is 92 psia. Calculate the work if the process of the compression is isothermal.
A. -180.5 hp B. -179.5 hp C. -227.6 hp D. -228.6 hp

54. The fuel oil has the ff analysis:

C = 89% N2 = 2% H2 = 8% S = 1%
With 3% excess air, what is the actual amount of air needed to burn the fuel oil?
A. 13.17 kgair / kgfuel B. 13.47 kgair / kgfuel
C.14.47 kgair / kgfuel D. 14.17 kgair / kgfuel

55. A pump discharges 550 gpm of water to a height of 35 ft. With an efficiency of 80%, what is the power
input?
A. 6.09 hp B. 6.32 hp C. 4.74 hp D. 4.94 hp

56. A room ontains air at 20˚C and 96 kPa at a relative humidity of 75%. Determine the enthalpy of moist
air.
where, (Psat @ 20˚C = 2.339 kPa)
(hg @ 20˚C = 2538.1 kJ/kgda)
A. 45.919 kJ/kgda B. 45.515 kJ/kgda
C. 49.515 kJ/kgda D. 41.815 kJ/kgda
Given: Unsaturated air (0% < Ø < 100%)
td = 20˚C; Pt = 96 kPa; Ø = 75%

57. A piston moves inside the cylinder at a velocity of 6.0 m / s. The 160 mm diameter piston is centrally
located within the 160.2 mm inside diameter cylinder. The film of oil is separating the piston from the
cylinder has an absolute viscosity of 0.4 N-s / m2. Assuming a linear velocity profile, find the shear stress in
the oil. ( T = μ (v / H) )
A. 50,000 N / m2 B. 40,000 N / m2 C. 24,000 N / m2 D. 34,000 N / m2

58. A centifugal pump with a 3ft impeller diameter operates at 800 rpm. If the speed is to be increased at
1200 rpm, determine the impeller diameter that should be used so that the sam shaft input power would be
required.
A. 5.32 ft B. 2.35 ft C. 5.23 ft D. 2.93 ft

59. Determine the mass of water vapor contained in a 150 m 3 room at 100 kPa, 23˚C and 40% relative
humidity. From Steam Tables: Psat @ 23˚C = 2.810 kPa.
A. 1.6342 kg B. 1.9342 kg C. 1.2342 kg D. 2.2342 kg

60. What is the power of the pump, hp, if it delivers 925 gal / min of water against a head of 15 m?
A. P = 15.38 hp B. P = 16.38 hp C. P = 10.5 hp D. P = 11.5 hp

61. Kerosene is pumped into an aircraft fuel tank through a hose that has an inside diameter of 4 cm. If the
velocity of the kerosene is 8 m / s through the hose, determine the mass flow rate. Assume that kerosene has
a density of 800 kg / m3.
A. 7.06 kg / s B. 7.56 kg / s C. 8.06 kg / s D. 8.56 kg / s

62. During the working stroke of an engine, the heat transferred out of the system was 150 kJ/kg of working
substances. The internal energy also decreased by 400 kJ/kg of working substance. Determine the work
done.
A. 250 kJ/kg B. 550 kJ/kg C. 600 kJ/kg D. 350 kJ/kg
63. During an experiment on Charles Law, the volume of gas trapped in the apparatus was 10,000mm 3 when
the temperature was 18˚C. The temperature of the gas was then raised to 85˚C. Determine the new volume
of the gas trapped in the apparatus if the pressure exerted on the gas remained constant.
A. 12302.41 mm3 B. 8128.49 mm3 C. 70833.33 mm3 D. 2117.64 mm3

64. Find the density of oil with a specific gravity of 1.6 in g / cm 3.

A. 15.68 g / cm3 B. 99.84 g / cm3 C. 0.8 g / cm3 D. 1.6 g / cm3

65. What is the absolute pressure if the gauge pressure is reading 9 Bar and the atmospheric pressure is 0.9
Bar?
A. 6.3 Bar B. 7.8 Bar C. 9.9 Bar D. 8.1 Bar

66. The tank of an air compressor has a volume of 3 ft 3 and is filled with air at a temperature of 40˚F. If a
gauge on tha tank reads 150 psig, what is the mass of the air in the tank?
A. 1.78 lbs B. 2.00 lbs C. 2.67 lbs D. 1.98 lbs

67. What is the mass of acetylene gas, V = 0.94 cu.ft, R = 59.35 ft-lb / lb˚R, T = 90˚F, P = 200psia.
A. 0.816 lbs B. 0.841 lb C. 0.829 lb D. 0.852 lb

68. Specific volume is the number of cubic meters of mixture per kilogram of dry air. If dry air has these
following properties: Ra = 287 J/kg-K, T = 303 K, Pa = 99.604 kPa. Solve for specific volume.
A. 0.873 m3 / kg B. 0.853 m3 / kg C. 0.953 m3 / kg D. 0.783 m3 / kg

69. A refrigerating system operates on the reversed Carnot Cycle. The higher temperature og the refrigerant
in the system is 120˚F and the lower is 10˚F. The capacity is 20 tons. Neglect losses. Determine the
coefficient of performance.
A. 2.732 B. 5.373 C. 7.372 D. 4.273

70. At a pressure of 60˚F, a motorbike tire is inflated to 33 psig. As it is driven along the C-5 road, the
temperature rises to 76˚F. Assuming the volume remains constant. Determine the final gauge pressure.
A. 34.47 psig B. 49.17 psig C. 35.00 psig D. 34.30 psig

71. Steam enters a turbine stage with an enthalpy of 3700 kJ/kg and a velocity of 80 m /s and leaves with an
enthalpy of 2864 kJ/kg with a velocity of 128 m / s. If the rate of steam flow through the turbine is 0.44 kg /
s, what is the work done in kW?
A. 365 kW B. 365.64 kW C. 366.0 kW D. 366.50 kW

72. Aluminum has a specific heat of 0.902 J / g-˚C. How much heat is lost when a piece of aluminum with a
mass of 23.984 g cools from a temperature of 415.0 ˚C to a temperature of 22.0˚C?
A. 8500 J B. 6000 J C. 80,000 J D. 7500 J

73. If the temperature of an air parcel is -20.5˚C, and its density is 0.690 kg / m 3, what is the pressure of the
air parcel?
A. 40 kPa B. 50 kPa C. 60 kPa D. 70 kPa

74. A car engine with a power output of 65 hp has a thermal efficiency of 24%. Determine the fuel
consumption rate of this car if the fuel has a heating value of 19,000 Btu / lb m.
A. 36.28 lb / hr B. 37.28 lb / hr C. 38.28 lb / hr D. 35.30 lb / hr

75. The thermal efficiency of a Carnot cycle operating between 170˚c and 620˚C is closest to:
A.44% B. 50% C. 63% D. 73%

76. Compute the humidity ratio of air at 70% relative humidity and 25˚C when the barometric pressure is
101.325 kPa. From steam table, Psat at 34˚C = 3.169 kPa
A. 0.014 kg water vapor / kg dry air
B. 0.14 kg water vapor / kg dry air
C.1.4 kg water vapor / kg dry air
D. 0.0014 kg water vapor / kg dry air

77. A 35.0 ml sample of gas is enclosed in a flask at 22 degrees Celsius. If the flask was placed in an ice
bath at 0 degrees Celsius, what would the new gas volume be if the pressure is held constant?
A. 31 ml B. 32.1 ml C. 32.39 ml D. 33.1 ml

78. A pressure gauge registers 50 psig in a region where the barometer reads 14.8 psia. Find the absolute
pressure in kPa.
A. 666.66 kPa B. 556.66 kPa C. 446.66 kPa D. 336.66 kPa

79. Consider 1 kg of air at 32˚C that expanded by a reversible polytropic process with n = 1.25 until the
pressure is lived. Determine the heat transfer. Specific heat at constant volume for air is 0.1786 kJ/kg-˚K.
A. 17.02 kJ heat rejected B. 17.02 kJ heat added
C. 7.05 kJ heat rejected D. 7.05 kJ heat added

80. Carnot cycle uses nitrogen (k = 1.399) as the working substance. The heat supplied is 54 kJ and the
adiabatic ratio is 1.0. Determine the heat rejected.
A. 10 kJ B. 32.4 kJ C. 21.6 kJ D. 54 kJ

81. A tank contains 20 kg of air at 200 kPa (gauge) and 20˚C. During heating process, the temperature of air
rises. For safety purposes, a technician installed a relief-type valve so that pressure of air inside the tank
never exceed 260 kPa (gauge). At what air temperature the relief valve will start releasing air?
A. 112˚C B. 92˚C C. 82˚C D. 102˚C

82. An air compressor takes in 9 kg / min of air at 98 kPa; v1 = 0.125 m3 / kg and discharges it at 680 kPa; v2
= 0.03 m3 / kg. The increase of internal energy is 93 kJ/kg and the work done on air is 163 kJ/kg; the change
in potential and kinetic energy are neglected. How much heat is transferred per kg of air?
A. 264.15 kJ/kg B. 61.85 kJ/kg C. 288.65 kJ/kg D. 78.15 kJ/kg

83. During a reversible process there are abstracted 317 kJ / s from 1.134 kg / s of a certain gas while the
temperature remains constant at 26.7˚C. For this gas, Cp = 2.232 kJ/kg-K and Cv = 1.713 kJ/kg-K. The initial
pressure is 586 kPa. Determine the final volume flow rate.
A. 0.301 m3 / s B. 0.03 m3 / s C.0.5 m3 / s D. 0.05 m3 / s

84. Flow of water in a pipe has a velocity of 10 meters per second. determine the velocity head of the water.
A. 50.1 meters B. 5.10 meters C. 8.20 meters D. 100 meters

85. A Diesel cycle has a cut-off ratio of 2.20 and a compression ratio of 10. Find the cycle efficiency.
A. 55.10% B. 59.735% C. 52.23% D. 62.37%

86. A Diesel cycle has an initial temperature of 27˚C. If the cut-off ratio is 2.50 and compression ratio is 12,
find the maximum cycle temperature.
A. 1634.4˚C B. 1753.44˚C C. 2010.3˚C D. 1983.4˚C

87. A diesel engine which takes in air at 1 Bar, 26˚C has a compression ratio of 19. Calculate the operating
clearance in percent.
A. 8.08 % B. 8.56% C. 7.52 % D. 5.55%

88. An Otto cycle has an initial pressure of 100 kPa and has a pressure of 400 kPa after adiabatic
compression. Find its cycle efficiency.
A. 32.70% B. 34.70% C. 36.70% D. 38.70%
89. An Otto cycle has a clearance of 8% and heat added of 1000 kJ. Find the heat rejected.
A.546 kJ B. 353 kJ C. 709 kJ D. 867 kJ

90. An Otto cycle has a heat rejected of 300 kJ and work of 700 kJ. Find the cycle efficiency.
A. 56% B. 60% C. 70% D. 50%

91. An Otto cycle has a pressure ratio of 7. What is the cycle compression ratio?
A. 5.18 B. 6.34 C. 7.34 D. 4.01

92. Find the power of the rotating shaft which develops a torque of 188 N-m at 1350 rpm.
A. 101.54 hp B. 53.63 hp C. 63.35 hp D. 35.63 hp

93. Determine the pressure exerted on a diver at 30 m below the free surface of the sea. Assume the
barometric pressure of 101 kPa and the specific gravity of sea water is 1.03.
A. 404 kPa B. 410 kPa C. 420 kPa D. 430 kPa

94. An air compressor has an inlet enthalpy of 35 Btu / lb and an exit enthalpy of 70 Btu / lb. The mass flow
rate is 3 lb / s. If the heat loss is 466.62 Btu / min, find the work input to the compressor.
A. 139.59 hp B. 149.59 hp C. 159.59 hp D. 169.59 hp

95. An automobile tire is inflated to 35 psig at 54˚F. After being driven, the temperature rises to 80˚F.
Determine the final gage pressure assuming that the tire is inflexible.
A. 36.51 psig B. 37.51 psig C. 38.51 psig D. 39.51 psig

96. A condenser vacuum gauge reads 100 mmHg when the barometer reads 760 mmHg. what is the absolute
condenser pressure in Bar?
A. 0.0213 B. 0.061 C. 0.213 D. 0.610

97. Water flows in a pipe at the rate of 10 kg / s. If the velocity of flow is 10 m / s, find the pipe diameter.
A. 30.23 mm B. 35.68 mm C. 38.39 mm D. 42.39 mm

98. What is the resulting pressure when one kilogram of air at 104 kPa and 98˚C is heated at constant
volume to 450˚C?
A. 202.67 kPa B. 194.67 kPa C. 186.53 kPa D. 198.65 kPa

99. Determine the degrees of superheat of steam at 101.325 kPa and 170˚C.
A. 50˚C B. 70˚C C. 60˚C D. 80˚C

100. Calculate the approximate enthalpy of water at 90˚C.

A. 366.83 kJ/kg B. 376.83 kJ/kg C. 386.83 kJ/kg D. 396.83 kJ/kg

101. A carnot cycle operates between 30˚C and 350˚C. Find the cycle efficiency.
A. 51.36% B. 63.45% C. 45.37% D. 76.45%

102. A Carnot cycle has a maximum temperature of 550˚F and minimum temperature of 100˚F. If the heat
added is 4200 Btu / min, find the horsepower input of the engine.
A. 34.53 hp B. 40.56 hp C.44.13 hp D. 65.40 hp

Problem:
103. A Carnot cycle has a sink temperature of 100˚F and a cycle efficiency of 70%. Find the temperature of
the heat source.
A. 1306.70˚F B. 1406.70˚F C. 1506.70˚F D. 1606.70˚F
104. Fifty kilograms of cooling water per second enter the condenser at 20˚C and leaves at 50˚C. Find the
heat carried away by water.
A. 1234.45 kW B. 5233.75 kW C. 2340.53 kW D. 3140.25 kW

105. Ten kilograms per second of steam enter the turbine with an enthalpy of 3200 kJ/kg and enter a
condenser with an enthalpy of 2500 kJ/kg in a Rankine cycle. If the turbine efficiency is 80% and the
generator efficiency is 90%, determine the power plant output.
A. 4320 kW B. 3213 kW C. 4056 kW D. 5040 kW

106. Determine the quality os team in a vessel containing 2 kg of saturated vapor and 8 kg of saturated
liquid.
A. 100% B. 20% C. 80% D. 60%

107. The condenser of a reheat power plant rejects heat at the rate of 600 kW. The mass flow rate of cooling
water is 5 kg / s and the inlet cooling water temperature is 35˚C. Calculate the condenser cooling water exit.
A. 43.45˚C B. 53.45˚C C. 63.66˚C D. 74.34˚C

108. A heat engine has a thermal efficiency of 50%. How power does the engine produce when heat is
transferred at a rate of 109 kJ / hr?
A. 50 MW B. 75 MW C. 139 MW D. 147 MW

109. One kilogram of air is compressed adiabatically and in a steady-flow manner. The compression
efficiency is 80% and the work done on the air is 265 kJ/kg. Compute the heat.
A. 212 kJ/kg B. 100 kJ/kg C. 0 kJ/kg D. 331.25 kJ/kg

Problem:
110. Three hundred kilojoules of heat flow by conduction from the outside to the inside of a cold storage in
one hour. If the temperature and all other conditions are the same, what is the heat flowing through the cold
storage room in two hours?
A. 600 kJ B. 900 kJ C. 300 kJ D. 1,200 kJ

Problem:
Determine the specific weight of air at 760 mmHg absolute and 22˚C?
A. 1.014 kg / m3 B. 1.316 kg / m3 C. 1.197 kg / m3 D. 1.266 kg / m3
Answer: Specific weight = 1.197 kg / m 3

Problem:
A refrigerating machine that is classified as a one-ton machine has the capacity to produce a cooling effect.
A. 3.517 kW B. 12,000 Btu / hr C. 211 kJ / min D. all of the above

Problem:
One kilogram of air 1.2 kg / cm2 at 30˚C is compressed according to the law of PV where C = 1.36 until its
volume 0.5 m3. If it is compressed isothermally, what will be the percent saving work?
A. 5.6% B. 8.7% C. 6.6% D. 8.2%\
Answer: Percent saving = 6.6%

Problem:
An electron strikes the screen of the cathode ray tube with a velocity of 10 to the 9 th power cm /s. Compute
its kinetic energy in ERGS. The mass of an electron is 9 x 10 -31 kg?
A. 1.5 x 10-10 ERG B. 9.5 x 10-10 ERG C. 3.5 x 10-10 ERG D. 4.5 x 10-10 ERG
Answer: KE = 4.5 x 10 ERG -10

Problem:
0.064 kg of octane vapor (MW = 114) is mixed with 0.91 kg of air (MW = 29.0) in the manifold is 86.1 kPa,
and the temperature is 290 K. Assume octane behaves ideally, what is the total volume of this mixture?
A. 0.895 cu.m B. 0.987 cu.m C. 0.565 cu.m D. 0.654 cu.m
Answer: V = 0.895 m 3

Problem:
Find the amount of electrical energy expanded raising the temperature of 45 liters of water by 75˚C. Assume
the efficiency heating equipment to be 90%
A. 5.35 kW-hr B. 4.36 kW-hr C. 0.565 kW-hr D. 0.54 kW-hr
Answer: Qin = 4.36 Kw-hr

Problem:
Water is discharged through a 1-inch diamter orifice under constant head of 2.1 ft the total discharge is 228
lbm. The jet is observed to pass through a point 2 ft downward and 4 ft away from vena contracta. Find the
CV.
A. 0.976 B. 0.758 C. 0.567 D. 0.845
Answer: CV = 0.976

Problem:
The density of Helium is 0.178 kg /m3 at STP. What is the density at 25˚C and 96 kPa?
A. 0.159 B. 0.358 C. 0.267 D. 0.545
Answer: A. 0.15 g / liter

Problem:
A substance has a density of 0.094 lb / ft3 at 100˚F and 2 atm. What pressure is needed to change the density
to 0.270 lb /ft3 at 250˚F?
A. 7.28 atm B. 8.32 atm C. 3.45 atm D. 5.25 atm
Answer: P2 = 7.28 atm
Problem:
If atmospheric air is 14.7 psia and 60˚F at sea level, what is the pressure at 12,000 ft altitude if air is
incompressible.
At 60˚F; the density of air is 0.0763 lbm / ft3; P1 = 14.7 psia
A. 5.42 psia B. 5.34 psia C. 6.72 psia D. 9.32 psia
Answer: P2 = 5.42 psia
Problem:
At what height will 68˚F ethyl alcohol rise in 0.005 inch internal diameter glass capillary tube? The density
of alcohol is 49 lb / ft3.
A. 0.3056 ft B. 0.453 ft C. 0.5434 ft D. 0.2435 ft
Answer: h = 0.3056 ft

Problem:
What is the velocity of sound in 150˚F (66˚C) air at a standard pressure?
Density of air at 150˚F is 0.064 lbm / ft3
A. 1215 ft /s B. 3245 ft / s C. 2345 ft /s D. 4321 ft / s
Answer: V = 1214.9 ft /s

Problem:
Oxygen is throttled at 140˚F from 10 atm to 5 atm. What is the temperature change?
A. 0 B. negative C. infinty D. 1
Answer: For throttled ideal gas, ΔT = 0

Problem:
A tire contains 1000 in3 of air at 24 psia and 32˚F. What pressure in the tire is needed if the temperature and
volume are increased to 35˚F and 1020 in3 respectively?
A. 23.57 psia B. 32.45 psia C. 43.54 psia D. 34.57 psia
Answer: P2 = 23.57 psia
Problem:
Determine the specific gravity of the carbon dioxide gas (molecular weight = 44) at 150˚F (66˚C) and 20
psia (138 kPa).
A. 1.67 B. 1.45 C. 1.87 D. 1.30
Answer: S.G. = 1.67
Problem:
A pump adds 550 ft of pressure head to 100 lbm / s of water. Compute the hydraulic power in horsepower.
A. 100 B. 150 C. 200 D. 300
Answer: P = 100 hp

Problem:
A pump driven by an electric motor moves 25 gal / min of water from reservoir A to reservoir B, lifting a
water a total head of 245 ft. The efficiencies of the pump and motor are 84% and 84% respectively. What is
the size of motor required?
A. 2.42 hp B. 1.24 hp D. 2.24 hp D. 2.34 hp
Answer: A. 2.42 hp

Determine the hydraulic diameter and the hydraulic radius for the open trapezoidal channel whose above
and bottom depths are 7 and 5 units respectively. The depth of the water is 3 units.
13.4 b. 1.59 c. 3.24 d. 5.3
Water is pumped a hillside into a reservoir. The pump discharges water at the rate of 6 ft/s and pressure of
150 psig. Disregarding friction, what is the maximum elevation (above the centreline of pump’s discharge)
of the reservoir’s water?
346.7 ft b. 546.7 ft c. 246.7 ft d. 146.7 ft
Water at 60 degFhas a specific gravity of 0.999 g/cc and akinematic viscosity of 1.12 centistoke. What is the
absolute viscosity in lbf-s/ft2?
2.34 x 10-5 b. 1.34 x 10-5 c. 3.34 x 10-5 d. 5.34 x 10-5
A steam engine operating between a boiler temperature of 220 deg C and a condenser temperature of 35 deg
C delivers 8Hp. If its efficiency is 30 percent of the for Carnot engine operating between this temperature
limits, how many calories are absorbed each second by the boiler?
12.7 kCal/s b. 11.43 kCal/s c. 10.56 kCal/s d. 9.57 kCal/s
How many kilograms of water at 0 deg C can a freezer with a coefficient of performance 5 make into ice
cubes at 0 deg C with a work of 3.6 MJ?
24 kg b. 34 kg c. 54 kg d. 15 kg
What is the change in entropy of 2 kg water molecules when transformed at a constant pressure of 1 atm
from water at 100 deg C to steam at the same temperature?
12.12 kJ b. 10.43 kJ c. 9.45 kJ d. 10.45 kJ
A copper of negligible heat capacity contains 1 kg of water just above the freezing point. A similar can
contains 1 kg of water just below the boiling point. Two cans are brought to into thermal contact. Find the
change in entropy of the system.
100 J/K b. 200 J/K c. 300 J/K d. 400J/K
In a gaseous mixture of 20 deg C, the partial pressures of the components are as follows: Hydrogen, 2000
mmHg; CO2, 150 mm Hg; methane 320 mm Hg; ethylene, 105 mm Hg. What is the mass fraction of
hydrogen?
0.026 b. 0.056 c. 0.076 d. 0.016
Cool water at 9 deg C enters hot-water heater from which warm water at room temperature of 80 deg C is
drawn at an average rate of 300 g/min. How much average electric power does the heater consume in order
to provide hot water at this rate?
4.18 kW b. 2.35 kW c. 3.31 kW d. 5.14kW
A hose shoots water straight up a distance of 2.5 m. The end opening on the hose has an area of 0.075 cm 2.
How much water comes out in 1 min?
34.18 L b. 22.35 L c. 31.5 L d. 5.14 L
The surface of household radiator has an emissivity of 0.55 and an area of 1.5 m2. At which rate is the
radiation absorbed emiited by the radiator when its temperature is 50 deg C?
308 W b. 509 W c. 108 W d. 409 W
It is required to pump water at 100 gpm from a large reservoir to the surface of another reservoir 400 ft
higher. What horsepower of the motor to drive the pump if the efficiency of the pump is 70%?
14.44 hp b. 15.55 hp c. 12.54 hp d. 10.54 hp
Compute he percent rating of a water tube boiler if the heating surface area is 500 m 2 and developed boiler
horsepower is 750.
136.5%b. 124.5% c. 138.7% d. 154.6%
A waste heat recovery boiler produces 4.8 Mpa (dry saturated) steam from 104 deg C feedwater. The boiler
receives energy from 7 kg/s of 954 º C dry air. After passing through the waste heat boiler, the temperature
of the air has been reduced to 343 ºC. Compute the volume flow rate of the steam in kg/s. Note: At 4.8
MPa,dry and saturated, h=2796 kJ/kg.
1.81 kg/s b. 1.92 kg/s c. 2.21 kg/s d. 1.46 kg/s
What is the power which a 3.5 MW natural gas engine can developed at an altitude of 1981.2 m assuming
that the presuure changes alone?
2.957 MW b. 3.247 MW c. 2.521 MW d. 4.466 MW
In a gaseous mixture of 20 ºC, the partial pressure of the components are as follows: Hydrogen =200 mm
Hg; Carbon dioxide= 150 mm Hg, Methane=320 mm Hg; Ethylene=105 mm Hg. What is the pressure of the
mixture?
755 mm Hg b. 255 mm Hg c. 345 mm Hg d. 800 mm Hg
A four stroke, direct injection diesel engine of 4” bore x 4.5” stroke develops 45 Hp at full load and 8 Hp
when running at idling load. Engine speed is 2200 rpm. Compute the mechanical efficiency.
56.52 % b.86.71 % c. 79.21 % d. 88.46%
The ultimate analysis of coal is given below:
C = 68.5% S = 1.5% Ash = 12%
H = 2.5% O = 3.5%
What is the higher heating value?
26280.63 kJ/kg b. 16250.63 kJ/kg c. 41380.53 kJ/kg d. 56398.32 kJ/kg
In a boiler design, it is desirable to have the flue gas exit temperature above the dewpoint. What is the
dewpoint temperature of the flue gas produced by combustion having the gravimetric analysis of:
N2 = 71.84% O2 = 3.61% CO2 = 20.35% H2O = 4.2%
Assume the air infiltration and leakage are negligible.
45 º C b. 40 ºC c. 39 ºCd. 24 ºC
Find the effective head of reaction turbine that develops 500BHP where flow through the turbine is 50 cfs.
Water enters at 20 fps with a 100 ft pressure head. The elevation of the turbine above the tailwater level is 8
ft?
136.52 ft b. 131.71 ft c. 114.2 ft d. 102.4 ft
Water is flowing through a pipe. A pitot-static gage registers 3 in Hg. What is the velocity of the water in
the pipe?
14.24 fps b. 13.42 fps c. 11.42 fps d. 10.24 fps

What is the terminal velocity of a 2” diameter aluminum sphere falling in air? Assume that the sphere has a
coefficient of drag of ___, the density of aluminum is 5.12 slug/ft 3, and the density of air is 0.00234 slug/ft3.
100 fps b. 177 fps c. 350 fps d. 1000 fps
In the real flow of air around a cylinder, the circulation is calculated to be 42.74 fps. If the free steam
velocity is 100 fps, what is the lift generated per foot of the cylinder?
10 lb/ft b. 42.75 lb/ft c. 120 lb/ft d. 322 lb/ft
A 5” diameter cylinder rotates at 3600 rpm. Air is flowing past the cylinder at 100fps. How much is the lift
on the cylinder per unit length?
23.65 lb/ft b. 1.25 lb/ft c. 11.75 lb/ft d. 20.75 lb/ft
A pump produces a head of 30 ft. The volumetric flow rate is 10 gpm. The fluid pumped oil with SG = 0.83.
How much energy does the pump consume in one hour?
8.7 kJ b. 17.2 kJ c. 168.9 kJ d. 203.6 kJ
A pump has an efficiency of 65%. It is driven by a 0.75 hp motor. The pump produces a pressure rise of
120 Pa in water. What is the required flow rate?
3.03 m3/s b. 4.04 m3/s c. 4.55 m3/s d. 4.66m3/s
The pressure drop across a turbine is 30 psi. The flow rate is 60 gpm. Calculate the power output of the
turbine.
0.41 hp b. 1.05 hp c. 2.54 hp d. 6.30 hp
If air is at pressure of 3200psf and at a temperature of 800 ºR, what is the specific volume?
9.8 ft3/lbm b. 11.2 ft3/lbm c. 13.3ft3/lbm d. 14.2 ft3/lbm
Steam at 1000 psf pressure and 300 ºR has a specific volume of 6.5 ft 3/lb and a specific enthalpy of 9800 lb-
ft/lb. Find the internal energy per pound mass of steam.
2500 lb-ft/lb b. 3300 lb-ft/lb c. 5400 lb-ft/lb d. 6900 lb-ft/lb
From steam tables, determine the average cp of steam at 10 kPa and 45.8 ºC.
1.79 kJ/kg-Cº b. 10.28 kJ/kg-Cº c. 30.57 kJ/kg-Cº d. 100.1 kJ/kg-Cº

A 10 m3 vessel initially contains 5m3 of liquid water and 5 m3 of saturated water vapor at 100 kPa. Calculate
the internal energy of the system using steam tables.
5 x 105 kJ b. 8 x 105 kJ c. 10 x 105 kJ d. 20 x 105 kJ
A vessel with a volume of 1 m contains liquid water and water vapor equilibrium at 600 kPa. The liquid
3

water has a mass of 1 kg. Using the steam tables, calculate the mass of the water of vapor.
0.99 kg b. 1.57 kg c. 3.16 kg d.2.54 kg
Calculate the entropy of steam at 60 psia with a quality of 0.6
0.4274 BTU/lb-R b. 0.7303 BTU/lb-R c. 1.1577 BTU/lb-R d. 1.2172 BTU/lb-R
The first law of thermodynamics is based on which of the following principles?
Conservation of mass
The enthalpy-entropy relationship
Action-reaction
Conservation of energy
The general energy equation for an open system involves the following five terms:
Accumulation of energy
Net energy transfer by work (standard sign convention)
Net energy transfer by heat (standard sign convention)
Transfer of energy in by mass flow
Transfer of energy out by the mass flow
Using the standard sign conventions, what is the proper arrangement of these terms for the general energy
equation satisfying the first law of thermodynamics?
I=-II+III+IV-V b. I=II+III+IV-V c. I=II+III+IV-V d. I=II-III-IV+V
What is the value of the work done for a closed, reversible, isometric system?
zero b. positive c. negative d. positive or negative

The expansion of a gas through a plug at a high enough pressure results in a temperature rise, while at lower
pressure, a temperature drop occurs. The Joule-Thompson coefficient is defined as the ratio of change in
temperature to the change in pressure. The temperature at which Joule-Thompson coefficient changes from
positive to negative is called the inversion temperature. When Joule-Thompson coefficient is negative
which of the following statements is true?
Gases may be liquified
Only trace liquification is possible
No liquification is possible
Liquification can be obtained only with a catalyst
A 5m3 vessel initially contains 50 kg of water and saturated vapor at total internal energy of 27300 kJ.
Calculate the heat requirement to vaporize all of the liquid.
100000 kJ b. 200000 kJ c. 300000 kJ d. 400000 kJ
Find the change in internal energy of 5 lb of oxygen gas when the temperature changes from 100 ºF to 120
ºF. cv = 0.157 BTU/lbm-R
14.7 BTU b. 15.7 BTU c. 16.9 BTU d. 147 BTU
Water is being heated by a 1500W heater. What is the rate of change in temperature of 1 kg of the water?
0.043 K/s b. 0.179 K/s c. 0.357 K/s d. 1.5 K/s
One kilogram of water is heated by 300 BTU of energy. What is the chabge in temperature, in K?
17.9 K b. 71.4 K c. 73.8 K d. 75.4 K

Determine the change in enthalpy per lbm of nitrogen gas as its temperature changes from 500 ºF to 200 ºF,
cp= 0.2483 BTU/lbm-ºR.
A. -74.49 BTU/lbm C. -68.47 BTU/lbm
B. -72.68 BTU/lbm D. 63.78 BTU/lbm

Answer: A

calculate the change in enthalpy as 1 kg of nitrogen is heated from 1000 K to

1500 K, assuming the nitrogen is an ideal gas at a constant pressure. The temperature – dependent specific
heat of nitrogen is:
cp = 39.06 - 512.79T -1.5 + 1072.7T -2 – 820.4T -3
cp is in kJ/kmole-K, and T is in K
A. 600 kJ C. 800 kJ
B. 700 kJ D. 900 kJ

Answer: B

What is the resulting pressure when one pound of air at 15 psia and 200 ºF is heated at constant volume to
800 ºF?
A. 15 psia C. 38.4 psia
B. 28.6 psia D. 52.1 psia
Answer: B

What horsepower is required to isothermally compress 800 ft 3 of air per minute from 14.7 psia to 120 psia?
A. 28 Hp C. 256 Hp
B. 108 Hp D. 13900 Hp

Answer: B

Calculate the work done by the system in which 1 kg mole of water completely evaporates at 100 ºC and 1
atmosphere pressure.
A. 1000 kJ C. 2490 kJ
B. 2130 kJ D. 3050 kJ

Answer: D

What is the equation for a work done by a constant temperature system?

A. W = mRT ln (V2-V1) C. W = mRT ln V2 / V1
B. W = mR (T2-T1) ln V2 / V1 D. W = RT ln V2 / V1

Answer: C

Twenty grams of oxygen (O2) are compressed at a constant temperature of 30 ºC to 5 % of their original
volume. What work is done on the system?
A. 824 cal C. 944 cal
B. 924 cal D. 1124 cal

Answer: D

Helium (R =0.4968 BTU/lbm-ºR) is compressed isothermally from 14.7 psia and 68 ºF. The compression
ratio is 4. Calculate the work done by the gas.
A. -1454 BTU/lbm C. -187 BTU/lbm
B. -364 BTU/lbm D. 46.7 BTU/lbm

Answer: B

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 m 3 to 0.10 m 3 at a constant pressure of 200 kPa. Calculate the work done by the
system.
A. 8 kJ C. 12 kJ
B. 10 kJ D. 14 kJ

Answer: C

A piston-cylinder system contains a gas which expands under a constant pressure of 1200 lbf/ft 2. If the
piston is displaced 12 during the process, and the piston diameter is 24”, what is the work done by the gas
on the piston?
A.1768 ft-lbf C. 2387 ft-lbf
B.1890 ft-lbf D. 3768 ft-lbf

Answer: D

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 m 3 to 0.10 m 3. The pressure varies such that PV = constant, and the initial pressure
is 200 kPa. Calculate the work done by the system.
A.6.80 kJ C. 9.59 kJ
B.7.33 kJ D. 12.0 kJ

Answer: B

How does an adiabatic process compare to an isentropic process?

A. adiabatic: heat transfer = 0; isentropic: heat transfer ≠ 0.
B. adiabatic: heat transfer ≠ 0; isentropic: heat transfer = 0.
C. adiabatic: reversible; isentropic: irreversible.
D. both: heat transfer = 0; isentropic: reversible.

Answer: D

What is true about the polytropic exponent n, for a perfect gas undergoing an isobaric process?
A. n > 0 C. n → ∞
B. n < 0 D. n = 0

Answer: D

In an isentropic compression, P1 = 200 psia, P2 = 300 psia, V1 = 10 in3, and 1.4 = ‫ﻻ‬, find V2.
A. 3.509 in3 C. 5.000 in3
B. 4.500 in 3
D. 6.095 in3

Answer: D

In an adiabatic, isentropic process, P1 = 200 psi, P2 = 300 psi, and T1 = 700 ºF. Find T2 using 1.4 = ‫ﻻ‬.
A. 576 ºR C. 680 ºR
B. 590 ºR D. 786 ºR

Answer: D

Air undergoes an isentropic compression from 14.7 psia to 180.6 psia. If the initial temperature is 68 ºF and
the final temperature is 621.5 ºF, calculate the work done by the gas.
A. -138.2 BTU/lbm C. 0 BTU/lbm
B. -94.8 BTU/lbm D. 94.8 BTU/lbm

Answer: B

Nitrogen is expanded isentropically, its temperature changes from 620 ºF to 60 ºF. Find the pressure ratio
(P1/P2).
A. 0.08 C. 26.2
B. 12.9 D. 3547

Answer: B

Nitrogen is expanded isentropically, its temperature changes from 620 ºF to 60 ºF. The volumetric ratio is
V1/V2 = 6022, and the value of R for nitrogen is 0.0787 BTU/lbm-ºR. What is the work done by the gas?
A. -1112.7 BTU/lbm C. 1112.7 BTU/lbm
B. -99.22 BTU/lbm D. 99.22 BTU/lbm

Answer: D

An isobaric steam generating engine process starts with saturated liquid at 20 psia. The change in entropy is
equal to the initial entropy. What is the change in enthalpy during the process? ( Hint: Not all of the liquid is
vaporized)
A. -230.4 BTU/lbm C. 0 BTU/lbm
B. 230.4 BTU/lbm D. 196.2 BTU/lbm

Answer: B

A cylinder and piston arrangement contains saturated water vapor at 110 ºC. The vapor is compressed in a
reversible adiabatic process until the pressure is 1.6 MPa. Determine the work done by the system per
kilogram of water.
A. -637 kJ/kg C. 432 kJ/kg
B. -509 kJ/kg D. 330 kJ/kg

Answer: C

Helium is compressed isothermally from 14.7 psia and 68 ºF. The compression ratio is 4. Calculate the
change in entropy of the gas given that RHe = -0.4961 BTU/lbm-ºR.
A. -2.76 BTU/lbm-ºR C. 0 BTU/lbm- ºR
B. –0.689 BTU/lbm-ºR D. 0.689 BTU/lbm-ºR

Answer: B

For an ideal gas, what is the specific molar entropy change during an isothermal process in which the
pressure changes from 200 kPa to 150 kPa?
A. 2.00 J/mole.K C. 2.79 J/mole.K
B. 2.39 J/mole.K D. 3.12 J/mole.K

Answer: B

200 g of water are heated from 5 ºC to 100 ºC and vaporized at a constant pressure. The heat of vaporization
of water at 100 ºC is 539.2 cal/g. the heat capacity at constant pressure, c p is 1.0cal/g.K. determine the total
change in entropy.
A. 248.2 cal/K C. 348.0 cal/K
B. 298.2 cal/K D. 398.2 cal/K

Answer: C

A Carnot engine operates between 800 ºR and 1000 ºR. What is the thermal efficiency?
A. 20 % C. 40 %
B. 30 % D. 50 %

Answer: A

A device produces 37.5 Joules per cycle; there is one power stroke per cycle. Calculate the power output if
the device is run at 45 rpm.
A. 4.69 W C. 28.125 W
B. 14.063 W D. 275.625 W

Answer: C

A steam generator produces saturated steam at 100 psia from saturated liquid at 14.7 psia. If the heat source
is bath at 340 ºF that provides 800 BTU/lbm, which of the following is true?
A. The device cannot work because the pressure gradient is greater than zero.
B. The device can work, but is inefficient.
C. The device violates the first law of thermodynamics.
D. The device violates the second law of thermodynamics.
Answer: C

An engine burns a liter of fuel each 12 minutes. The fuel has a specific gravity of 0.8, and heating value of
45 MJ/kg. The engine has an efficiency of 25 %. What is the brake horsepower of the engine?
A. 12.5 hp C. 16.76 hp
B. 15.63 hp D. 20.95 hp

Answer: C

A device that is meant to extract power from waste process steam starts with a steam of 75 % quality at 100
psia. The exit conditions of the steam are 70 %quality at 14.7 psia. Which of the following statement is
true?

I. This device violates the first law of thermodynamics.

II. This device violates the second law of thermodynamics.
III. This device generates positive net power.
IV. This device generates no net power.

A. I C. III
B. II D. IV

Answer: C

An engineer device a scheme for extracting some power from waste process steam. The steam enters the
device at 100 psia and quality 75 % and exits at 14.7 psia and 65 % quality. Which of the following
statements are true?

I. This device produces 155 BTU/lbm of work.

II. This device violates the second law of thermodynamics.
III. This device violates the first law of thermodynamics

A. I C. III
B. II D. I and II

Answer: D

A refrigeration system produces 150 BTU/lbm of cooling. In order to have a rating of 1 ton of refrigeration,
what must be the mass flow rate of the vapor? (1 ton of refrigeration = 12000 BTU/hr, approximately the
rate required to freeze 1 ton of ice in a day.)
A. 2.2 lbm/hr C. 80 lbm/hr
B. 15 lbm/hr D. 360 lbm/hr

Answer:

The mole is the basic unit of measurement in chemistry. Which of the following is not equal to or the same
as one mole of the substance indicated?
A. 6.02 x 1023 of oxygen (O2) molecules C. 16 g of oxygen (O2) molecules
B. 12 g of carbon atoms D. 1 g of hydrogen (H) atoms
Answer: C

The valve between a 9 liter tank containing gas at 5 atmospheres and a 6 liter tank containing gas at 10
atmospheres is opened. What is the equilibrium pressure obtained in the two tanks at constant temperature?
Assume ideal gas behavior.
A. 5 atm C. 7 atm
B. 6 atm D. 8 atm

Answer: C

A bicycle that has a volume of 600 cm3. It is inflated with CO2 to a pressure of 80 psi at 20 ºC. How many
grams of CO2 are obtained in the tire?
A. 3.83 g C. 5.98 g
B. 4.83 g D. 6.43 g

Answer: C

On a hot day, the temperature rises from 50 ºF early in the morning to 99 ºF in the afternoon. What is the
ratio of the concentration in moles/ft3 of helium in a spherical balloon in the afternoon to the concentration
of helium in the balloon in the morning?
A.0.51 C. 0.91
B.0.69 D. 1.10

Answer: C

When 0.5 g of a liquid is completely evaporated and collected in a 1 liter manometer, the pressure is 0.25
atmospheres and the temperature is 27 ºC. Assuming ideal gas behavior, determine the molecular weight.
The gas constant is R = 0.0821 atm/mole.K.
A. 2 g C. 12.3 g
B. 2.2 g D. 49.2 g

Answer: D

Two hundred milliliters of oxygen gas (O2) are collected over water at 23 ºC and a pressure of 1 atmosphere.
What volume would the oxygen occupy dry at 273 K and 1 atmosphere?
A.179.3 mL C.190.9 mL
B.184.4 mL D. 194.5 mL

Answer: A

The atomic weight of hydrogen is 1 gram per gram-atom. What is the mass of a hydrogen atom?
A.1.66 x 10 -24 g/atom C. 1.0 x 10 -23 g/atom
B. 6.02 x 10 g/atom
-10
D. 1 g/atom

Answer: A

Calculate the theoretical density of copper given that the unit cell is face-centered cubic and the lattice
parameter is 361 Å. The atomic weight of copper is 63.5 g/mole.
A.4.49 g/cm C. 8.87 g/cm
B. 7.86 g/cm D.8.97 g/cm

Answer: D
Determine the planar density of copper atoms in the (100) plane given that the unit cell is face-centered
cubic and the lattice parameter is 3.61 Å.
A.7.68 x 10 18 atoms/m2 C. 2.30 x 10 19 atoms/m2
B. 1.53 x 10 atoms/m
19 2
D. 3.84 x 10 19 atoms/m2

Answer: B

A sample of face-centered cubic nickel (Ni) was placed in an X-ray beam of wavelength λ = 0.154 nm. If
the lattice parameter for Ni is 0.325 nm, what is the first order angle of diffraction?
A. 5.68 º C. 12.6 º
B. 6.97 º D. 19.0 º

Answer: C

An open chamber rests on the ocean floor in 160 feat of sea water (sp.gr = 1.03). What air pressure in psig
must be maintained inside to exclude water?
A. 45.2 C. 71.4
B. 60.9 D. 93.2

Answer: C

Pressure in lbf/ft2 at a depth of 300 feet in fresh water is nearest to:

A. 5360 psf C. 18700 psf
B. 12900 psf D. 32400 psf

Answer: C

What head in feet of air, at ambient condition of 14.7 psia and 68 ºF, is equivalent to 2 psia?
A. 146 C. 3840
B. 395 D. 1560

Answer: C

With a normal barometric pressure at a sea level, atmospheric pressure at an elevation of 4000 feet is nearest
to
A. 26” Hg C. 27” Hg
B. 28” Hg D. 29” Hg

Answer: A

An open topped cylindrical water tank has horizontal circular base 10 feet in diameter. When filled to a
height of 8 feet, the force in lbs exerted on its base is nearest to:
A. 3900 C. 26000
B. 7800 D. 39000

Answer: D

Each connection between a 90 degree elbow and the 6” diameter pipeline to which is connected must resist
what net tensile force in lbs under static, non-flow conditions if the line is pressurized to 100 psig?
A. 710 C. 2000
B. 830 D. 2800
Answer: D

A circular access port 2 feet in diameter seals an environmental test chamber that is pressurized to 15 psi
above external pressure. What force in lbs does the port exert upon its retaining structure?
A. 1700 C. 2300
B. 3700 D. 6800

Answer: D

Ice in an iceberg has a sp.gr of 0.922. When floating in sea water (sp.gr = 1.03), its exposed volume % is
nearest to
A. 5.6 C. 8.9
B. 7.4 D. 10.5

Answer: D

A floating cylinder 8cm diameter and weight 950 grams is placed in a cylindrical container 20 cm in
diameter partially full of water. The increase in the depth of water in the container is due to placing the float
in it is:
A. 10 cm C. 3 cm
B. 5 cm D. 2 cm

Answer: C

The theoretical velocity generated by a 10 foot hydraulic head is:

A. 12.2 ft/sec C. 25.4 ft/sec
B. 17.9 ft/sec D. 29.2 ft/sec

Answer: C

What is the static head corresponding to a flow velocity of 10 ft/sec?

A. 1.55 ft C. 2.05 ft
B. 1.75 ft D. 2.25 ft

Answer: A

Normal boiling point of liquid oxygen is 90 ºK. What is this temperature in R?

A. -330 ºR C. 162 ºR
B. -183 ºR D. 168 ºR

Answer: C

An airtight closed box of weight P is suspended from a spring balance. A bird of weight W is placed on the
floor of the box and balance reads W + P. If the bird flies around the box at a constant elevation without
accelerating, what is the balance reading
A. P C. P + W2
B. P - W D. P + W

Answer: D
A machine with a 100 horsepower engine is capable of lifting a 10000lb load a height of 20 feet in 10
seconds. What is the efficiency of this machine?

Answer: 36.4 percent

Two barges, one weighing 10 tons, the other weighing 20 tons are connected by a cable in quiet water.
Initially the barges are at 100 feet apart. The cable is reeled in until the barges are 50 feet apart. If the
friction is negligible, calculate the distance covered by the 10 ton barge.

Answer: 33.3 ft

A 60 ton car is to travel around a curve of radius 3000 ft at a speed of 60 mph. By how much must the outer
rail be elevated in order that the reaction against the track may be perpendicular to the plane of the rails?
The track is standard gage of 4’ - 8½”

Answer: 4.53 in

A projectile weighing 100 pounds strikes the concrete wall of a fort with an impact velocity of 1200 feet per
second. The projectile comes to rest in 0.01 second, having penetrated the 8 foot - thick wall to a distance of
6 feet. What is the average force exerted to the wall by the projectile?

Answer: 3.73 x 105 lbs

Two 3 – lb weights are connected by a massloss string hanging over a smooth, friction peg. If a third weight
of 3 lbs is added to one of the weights and the system is released; by how much is the force on the peg
increased?

Answer: 2 lbs

A gas bubble rising from the ocean floor is 1 inch in diameter at a depth of 50 feet. Given that sp.gr of sea
water is 1.03, the buoyant force in lbs being exerted on the bubble at this instant is nearest to:
A.0.014 C. 0.076
B. 0.020 D. 0.14

Answer: B

Draft, in inches of water differential pressure is generated at the base of a 100 foot stack filled with 500 ºF
gases (assume same molecular weight as air due to differential specific gravity.)
(Under ambient conditions of 14.7 psia and 68 ºF, air sp.wt. is 0.075 lbf/ft3.) The draft is nearest to:
A.0.30” water C. 1.00” water
B. 0.65” water D. 1.50” water

Answer: B

Ice in an iceberg has a sp.gr of 0.922. When floating in sea water (sp.gr = 1.03), its exposed volume % is
nearest to
A. 5.6 C. 8.9
B. 7.4 D. 10.5

Answer: D

A cylinder of cork is floating upright in a container partially filled with water. A vacuum is applied to the
container such that the air within the vessel is partially removed. The cork will
A. rise somewhat in the water. C. remain stationary
B. sink somewhat in the water D. turn over on its side

Answer: B

A floating cylinder 8cm diameter and weight 950 grams is placed in a cylindrical container 20 cm in
diameter partially full of water. The increase in the depth of water in the container is due to placing the float
in it is:
A. 10 cm C. 3 cm
B. 5 cm D. 2 cm

Answer: C

A block of wood floats in water with 6 inches projecting above the water surface. If the same block were
placed in alcohol of specific gravity 0.82, the block would project 4 inches above the surface of the alcohol.
Determine the specific gravity of the wood block.

Answer: 0.603
Air flows in a long length of 1” diameter pipe. At one end the pressure is 30 psia, the temperature is 300 ºF
and the velocity is 30 ft/sec. At the other end the pressure has been reduced by friction and heat loss to
20psia. The mass flow rate in lb/sec at any section along the pipe is nearest to:
A. 0.02 C. 0.37
B. 0.1 D. 1.5

Answer: A

Water flow rate a long ½ in i.d hose at 3 gallons per minute. Water velocity in ft/sec is nearest to:
A. 1 C. 10
B. 5 D. 20

Answer: B

Theoretical horsepower required to pump water at 100 gallons per minute from a large reservoir to the
surface to another large reservoir 400 feet higher is nearest to:
A. 6 Hp C. 18 Hp
B. 10 Hp D. 36 Hp

Answer: B

Horizontal stream of water with a cross sectional area of 0.1 ft 2 and a velocity of 10 ft/sec has kinetic energy
in ft-lbf/sec nearest to:
A. 2500 C. 11700
B. 8200 D. 56000

Answer: B

Water tank consist of a right circular cone that has a central axis vertical and is vertex at the bottom. The
radius at the top is ___ feet, the height is 50 feet, and the water is 15 feet deep. Determine the work required
to pump all the water to the level of the cone.

Answer: 342000 ft-lb

Stream of fluid with a mass flow rate of 2 slugs/sec and a velocity of 20 ft/sec to the right has its direction
reversed 180 º in a U- tube. The dynamic force in lbf exerting by the fluid on the fitting is nearest to:
A. 40 C. 514
B. 80 D. 1288
Answer: B

The thrust in lbf generated by an aircraft jet engine on takeoff per 1 lb m/sec exhaust products, whose
velocity has been increased from essentially 0 to 500 ft/sec, is nearest to which of the following:
A. 15 C. 360
B.130 D. 710

Answer: A

An orifice 2” in diameter discharge fluid from a tank with a head of 15 feet. Discharge rate q measured at
0.5 cfs. Actual velocity at the vena contracta, v.c is 29.0 ft/sec. The coefficient of discharged, C d is nearest
to:
A. 0.62 C. 0.79
B.0.74 D. 0.86

Answer: B

At normal atmospheric pressure, the maximum height in feet that a non volatile fluid of specific gravity of
0.80 may be siphoned is nearest to:
A. 12 C. 28
B.20 D. 42

Answer: D

Water flow rate in a 6 inches diameter pipe is measured with a differential pressure gage connected between
a static pressure tap in the pipe wall and a pilot tube located at the centerline. Which volume flow rate q in
cfs results in a differential pressure of 1 psi?
A. 0.2 C. 15.6
B.2.4 D. 28.2

Answer: B

A cylinder fitted with a weightless, frictionless piston contains m pounds of air at a temperature T 1, volume
V1, and ambient pressure Pa. Heat is added until the air in the cylinder has a temperature T 2, a volume V2,
and ambient pressure Pa. The specific heat of air in a constant pressure is c p, and the specific heat of air at
constant volume is cv. The heat transferred during the process is:
A. mcp (T2-T1) C. mcp (T2-T1) + Pa (V2-V1)
B. mcv (T2-T1) - Pa (V2-V1) D. mcv (T2-T1) + Pa (V2-V1)

Answer: D

A non flow (closed) closed system contains 1 lb of an ideal gas (c p = 0.24, cv = 0.17). The gas temperature is
increased by 10 ºF while 5 BTU of work done by the gas. What is the heat transfer in BTU?
A. - 3.3 C. + 6.7
B. - 2.8 D. + 7.4
Answer: C

Shaft work of -15 BTU/lb and heat transfer of -10 BTU/lb change enthalpy of a system by
A. -25 BTU/lb C. -10 BTU/lb
B. -15 BTU/lb D. +5 BTU/lb

Answer: D
55000 galloons of water pass through a heat exchanger and absorb 28000000 BTU’s. The exit temperature
is 110 ºF. The entrance water temperature in ºF is nearest to:
A. 49 C. 68
B. 56 D. 73

Answer: A

The mass flow rate of Freon 12 through a heat exchanger is 10 pounds per minute, enthalpy of Freon entry
is 102 BTU/lb and Freon exit is 26 BTU/lb. Water coolant is allowed to raise 10 ºF. The water flow rate in
pounds/minute is:
A. C. 83
B. D. 112

Answer: B

An 8.8 grams of finely divided aluminum is heated to 98.3 ºC and dropped into 76.2 grams of water at 18.6
ºC contained in a calorimeter. The final temperature of the mixture is 27.4 ºC. The mass of the calorimeter is
123 grams, and its specific heat may be taken as 0.092 cal g -1deg -1. The combined thermal capacity of the
thermometer and metal stirrer is 6.5 cal deg -1. Assuming the heat is lost from the system; calculate the mean
specific heat of the aluminum for the above temperature range.

Answer: 0.217

In terms of QH (heat from high temperature source) and QL (heat to low temperature sink), the net work of a
carnot cycle is:
A. W = QH - QL C. W = QL / (QH - QL)
B. W = (QH - QL) / QL D. W = QL – QH

Answer: C

The maximum thermal efficiency that can be obtain in an ideal reversible heat engine operating between
1540 ºF and 340 ºF is nearest to:
A. 100 % C. 78 %
B. 60 % D. 40 %

Answer: B
A 3 HP refrigerator or heat pump operates between 0 ºF to 100 ºF. the maximum theoretical heat that can be
transferred from the reservoir is nearest to:
A. 7600 BTU/hr C. 23000 BTU/hr
B. 13000 BTU/hr D. 35000 BTU/hr

Answer: D

A carnot cycle heat engine operating between 1540 ºF to 440 ºF has an efficiency of:
A. 55 % C. 35 %
B. 45 % D. 29 %

Answer: A

Second law limitation on the maximum horsepower output from any power unit burning 1000000 BTU/hr
of fuel with high and low temperature extremes of 1540 ºF and 40 ºF is:
A. 98 C. 1140
B. 295 D. 3830

Answer: B
A heat pump installation is used to warm a steam of circulating air residence to 100 ºF; an outside ambient
of 35 ºF is considered the available heat source. A heating requirement of 90000 BTU/hr is necessary to
maintain a comfortable temperature in the living space.
(a) Determine the absolute minimum electrical requirement in HP to operate a heat pump delivering 90000
BTU/hr under these conditions.
(b) Determine the electrical requirement in kW to accomplish the same heat by resistance heating.

Answer: 4.65 HP and 3.47 kW

A carnot cycle engine operates between 1540 ºF and 40 ºF and rejects 250 BTU/lb to the low temperature
reservoir or heat sink. Maximum entropy changes in BTU/lb. ºR of the working fluid for any process in the
cycle is:
A. 0 C. 0.50
B. 0.25 D. 1.0

Answer: C

A high velocity flow of gas at 800 ft/sec possesses kinetic energy nearest to which of the following?
A. 1.03 BTU/lbm C. 9.95 BTU/lbm
B. 4.10 BTU/lbm D. 12.8 BTU/lbm

Answer: D

A carnot engine operating between 70 ºF and 2000 ºF is modified solely by raising the high temperature 150
ºF and raising low temperature by 100 ºF. Which of the following statements is false?
A. thermodynamic efficiency is increased.
B. more work is done during the isothermal expansion.
C. more work is done during the isentropic compression.
D. more work is done during the reversible adiabatic expansion.

Answer: A

An open or flow process (across a fixed control volume) in the absence of PE and KE changes, which of the
following represents the shaft work done during a polytrophic process?
A.W = (k / 1-k) (P2V2 – P1V1) = (k / 1-k) mR (T2 –T1) = (k / 1-k) mRT1 [(P2/P1) (k / 1-k) - 1]
B.W = P1V1 ln (P1/P2) = P1V1 ln (V2/V1) = mRT ln (V2/V1) = mRT ln (P1/P2)
C.W = (n / 1-n) (P2V2 – P1V1) = (n / 1-n) mR (T2 –T1) = (n / 1-n) mRT1 [(P2/P1) (n / 1-n) - 1]
D.W = 0

Answer: C

In a closed system (with a moving boundary) which of the following represents work done during
isothermal process?
A. W = P (V2 - V1)
B. W = 0
C. W = P1V1 ln (P1/P2) = P1V1 ln (V2/V1) = mRT ln (V2/V1) = mRT ln (P1/P2)
D. W = (P2V2 – P1V1) / (1 – k) = mR (T2 –T1) / (1- k)

Answer: C

Work of a polytrophic (n = 1.21) compression of air (c p / cv = 1.40) in a system with moving boundary from
P1 = 15 psia, V1 = 1.0 ft3 to P2 = 150 psia, V2 = 0.15 ft3.
A.35.5 ft-lb C. 1080 ft-lb
B. 324 ft-lb D. 5150 ft-lb
Answer: D

Isentropic compression of 1 ft3 of air (cp / cv = 1.40), at 20 psia to a pressure of 100 psia gives a final volume
of:
A.0.16 ft3 C. 0.32 ft3
B. 0.20 ft3
D. 0.40 ft3

Answer: C

Determine the theoretical horsepower required for the isothermal compression of 800 ft 3/min of air from
14.7 to 120 psia.

Answer: 108 HP

A mixture at 14.7 psia and 68 ºF that is 30 % weight CO2 (m wt. = 44) and 7 % weight N2 (m wt. = 28) has a
partial pressure of CO2 in psia that is nearest to:
A. 2.14 C. 6.83
B. 3.15 D. 7.86

Answer: B

Given that molar cp of CO2 is 8.92 BTU/ (lb.mole.ºR), and molar cp of N2 is 6.95 BTU/(lb.mole.ºR),,the
calculated cp per pound of mixture containing 25 % vol. CO2 and 75 % vol. N2 is:
A. 0.23 BTU/lb-ºR C. 5.21 BTU/lb- ºR
B. 2.23 BTU/lb-ºR D. 7.44 BTU/lb-ºR

Answer: A

Dry air has an average molecular weight opf 28.9, consisting of 21 moles - % O 2, 73 moles - % N2 and 1
mole - % (argon traces of CO2). Its calculated wt.% O2 is nearest to:
A. 21.0 C. 23.2
B. 22.4 D. 24.6

Answer: C

Sonic velocity (mach 1) at 50000 feet altitude in the standard upper atmosphere (- 67.6 ºF and 1.68 psia) is
nearest to:
A. 880 ft/sec C. 995 ft/sec
B. 917 ft/sec D. 1064 ft/sec

Answer: B

During complete stoichiometric combustion of 1 lb mole methane (Ch 4) with air, the number in lb moles of
nitrogen and other element that pass through the combustion zone is nearest to:
A. 0.79 C. 5.6
B. 3.9 D. 7.5

Answer: D
The temperature difference between the two sides of a solid rectangular slab of area A and thickness L as
shown below is ΔT. The heat transferred through the slab by conduction by time t is proportional to:
A. ALΔTt C. AL (t/ ΔT)
B. AL (ΔT/t) D. (AΔTt) / L

Answer: D

The heat loss per hour through 1 sq.ft of furnace wall 18” thick is 520 BTU. The wall temperature is 1900
ºF, and its average thermal conductivity is 0.61 BTU/hr.ft ºF,
The outside surface temperature of the wall is nearest to:
A. 100 ºF C. 600 ºF
B. 300 ºF D. 1000 ºF

Answer: C

A metal object at 120 ºF is set on an insulating pad to cool. The temperature initially falls from 120 ºF to
100 ºF in 12 minutes. Surroundings are at 65 ºF, find the time required for that object to continue to cool
from 98 ºF to 80 ºF. Assume negligible conduction and radiation losses in both cases.

Answer: 20.9 min

A shell and tube brine cooler cools 150 gallons of brine per minute from 60 ºF to 12 ºF, using ammonia at 5
ºF. The effective outside area of the tubes is 310 ft2. The brine ha specific gravity of 1.2 and specific heat of
0.70.
(a) Compute the rating of the cooler in tons of refrigeration.
(b) Compute the coefficient of heat transfer, U in BTU/ hr.ft ºF.

Answer: 21 TOR and 91.4

Which of the following is not a usual operation of the power per unit area Stefan – Boitzmann constant for
black body radiation?
A. 1.36 x 10 – 12 cal/ (sec.cm2. ºK4) C. 5.68 x 10 – 8 watts/ (m2. ºK4)
B. 5.68 x 10 ergs/ (sec.cm . ºK )
–8 2 4
D. 5.68 x 10 – 8 coulombs/ (sec.cm2. ºK4)

Answer: D