Study Set Content:
23. A 23 ton refrigeration system has a heat rejected of 100 kW. Find the energy efficiency ratio of the system.
A. 13.42
B. 14.42
C. 15.42
D. 16.42
B. 14.42
24. A 200 mm x 250 mm, 8-cylinder, 4-stroke diesel engine has a brake power of 150 kW. The mechanical efficiency is 80%. If two of the cylinders were accidentally cut off, what will be the new friction power?
A. 31.50 kW
B. 33.50 kW
C. 35.50 kW
D. 37.50 kW
D. 37.50 kW
25. If the energy efficiency ratio of the refrigeration system is 12.6, what is the COP of the system?
A. 3.69
B. 4.23
C. 5.92
D. 6.83
A. 3.69
26. An air compressor has a power of 40 kW at 4% clearance. If the clearance will increase to 7%, what is the new power?
A. 70 kW
B. 40 kW
C. 53 kW
D. 60 kW
B. 40 kW
27. What is the approximate value of temperature of water having enthalpy of 208 Btu/lb?
A. 138.67°C
B. 115.55°C
C. 258.67°C
D. 68.67°C
B. 115.55°C
28. Convert 750°R to K.
A. 390.33 K
B. 395.33 K
C. 410.33 K
D. 416.33 K
D. 416.33 K
29. An Otto cycle has a compression ratio of 8. Find the pressure during compression.
A. 18.38
B. 16.38
C. 14.38
D. 12.28
A. 18.38
30. A diesel cycle has a cut off ratio of 2.5 and expansion ratio of 4. Find the clearance of the cycle.
A. 9.11%
B. 5.55%
C. 11.11%
D. 15.15%
C. 11.11%
31. A dual cycle has an initial temperature of 30°C. The compression ratio is 6 and the heat
addition at constant volume process is 600 kJ/kg. If the cut-off ratio is 2.5, find the maximum temperature of the cycle.
A. 3638.50°C
B. 3365.50°C
C. 3565.50°C
D. 3965.50°C
B. 3365.50°C
32. A 3-stage air compressor compresses air from 100 kPa to 1000 kPa. Find the intercooler pressure between the 1st and 2nd stage.
A. 505.44 kPa
B. 108.44 kPa
C. 316.23 kPa
D. 215.44 kPa
D. 215.44 kPa
33. A 10-stage air compressor compresses air from 100 kPa to 800 kPa. Find the intercooler
pressure between the 1st and 2nd stage.
A. 282.84 kPa
B. 113.21 kPa
C. 123.11 kPa
D. 333.51 kPa
C. 123.11 kPa
34. A 3-stage air compressor compresses air from 100 kPa to 700 kPa. Find the intercooler
pressure between the 2nd and 3rd stage.
A. 365.88 kPa
B. 375.88 kPa
C. 385.88 kPa
D. 395.88 kPa
A. 365.88 kPa
35. Carnot cycle A, B and C are connected in series so that the heat rejected from A will be the heat added to B. and heat rejected from B will be added to C. Each cycle operates between 30°C and 400°C. If heat added to A is 1000 kW, find the work output of C.
A. 111.44 kW
B. 549.78 kW
C. 247.53 kW
D. 141.89 kW
A. 111.44 kW
36. Air compressed adiabatically from 30°C to 100°C. If the mass of air being compressed is 5 kg, find the change of entropy.
A. 1.039 kJ/K
B. 0.746 kJ/K
C. 0
D. 1.245 kJ/K
C. 0
37. Two kilogram of air in a rigid tank changes its temperature from 32°C to 150°C. Find the work done during the process.
A. 236
B. 170
C. 195
D. 0
D. 0
38. Determine the atmospheric pressure at a location where barometric reading is 740 mm Hg and gravitational acceleration is g = 9.7 m/s2. Assume the temperature of mercury to be 10°C, at which the density is 13,570 kg/m3
A. 99.45 kPa
B. 97.41 kPa
C. 95.44 kPa
D. 98.66 kPa
B. 97.41 kPa
39. The barometer of a mountain hiker reads 930 mbars at the beginning of a hiking trip and
780 mbars at the end. Neglecting the effect of altitude on local gravitational acceleration,
determine the vertical distance climbed. Assume g = 9.7 m/s2
.
A. 1274.21 m
B. 1289.00 m
C. 1267.34 m
D. 1583.34 m
B. 1289.00 m
40. The lower half of a 10 m high cylindrical container is filled with water and the upper half with oil that has SG = 0.85. Determine the pressure difference between the top and bottom if the cylinder.
A. 90.74 kPa
B. 92.74 kPa
C. 83.38 kPa
D. 98.10 kPa
A. 90.74 kPa
3. Find the enthalpy of Helium if its internal energy is 200 kJ/kg.
A. 144 kJ/kg
B. 223.42 kJ/kg
C. 333.42 kJ/kg
D. 168 kJ/kg
C. 333.42 kJ/kg
6. Compute the free aperture cross section in m³ for the ventilation of a machinery room if the mass of refrigerant is 9 kg.
A. 0.314
B. 0.414
C. 0.514
D. 0.614
B. 0.414
