A 2.2 kW refrigerator or heat pump operates between – 17oC and 38oC. Determine the maximum theoretical heat that can be transferred from thecold reservoir.a) 10.24 kWb) 12.44 kWc) 14.01 kWd) 14.24 kWSolution:LHLLTTTWQ−=()kW24.101738172732.2TTTWQLHHH=⎟⎠⎞⎜⎝⎛+−=⎟⎟⎠⎞⎜⎜⎝⎛−=2.Determine the final volume of the isentropic compression of 1 m3air from 20 kPaa to a pressure of 100 kPaa.a) 1.9047 m3b) 0.5253 m3c) 0.3168 m3d) 0.1061 m3Solution:()34.113k12112m3168.010020m1ppVV=⎟⎠⎞⎜⎝⎛=⎟⎟⎠⎞⎜⎜⎝⎛=3.What is the clearance of an ideal Otto engine if the efficiency is 40 % and k = 1.3?a) 21.18 %b) 12.27 %c) 22.28 %d) 23.28 %Solution:489.540.011e11r3.011k1k=⎟⎠⎞⎜⎝⎛−=⎟⎠⎞⎜⎝⎛−=−()()%28.22%1001489.51%1001r1ck=⎟⎠⎞⎜⎝⎛−=⎟⎟⎠⎞⎜⎜⎝⎛−=4.A 500 Hp internal combustion engine has a brake mean effective pressure of 551.5 kPa at full load. What is the friction power if the mechanicalefficiency is 85 %?a) 75 Hpb) 88.24 Hpc) 78.24 Hpd) 98.24 HpSolution:Hp24.8850085.0500BPBPBPIPFPm=−⎟⎠⎞⎜⎝⎛=−⎟⎟⎠⎞⎜⎜⎝⎛η=−=5.A fiber glass insulating board with thermal conductivity of 0.05 W/m-oC is to be used to limit the heat losses to 100 W/m2for a temperaturedifference of 150oC across the board. Determine the thickness of the insulating board.a) 57 mmb) 65 mmc) 56 mmd) 75 mmSolution:()()()mm75m075.0m/W100C150Cm/W05.0AqTkx2ook==⋅=⎟⎟⎠⎞⎜⎜⎝⎛∆=6.A Brayton cycle has a compression ratio of 11. Find the cycle thermal efficiency if the compression and expansion exponent is 1.25.a) 62.99%b) 45.09 %c) 49.05 %d) 69.22 %Solution:()()()()()()%09.45%1001111%100r11%100r11e25.01nkk1npthe=⎥⎥⎦⎤⎢⎢⎣⎡−=⎥⎥⎦⎤⎢⎢⎣⎡−=⎥⎥⎥⎦⎤⎢⎢⎢⎣⎡−=−−7.An air standard Otto cycle has a compression ratio of 10. The initial temperature is 30oC and initial pressure is 100 kPaa. If heat added is 1150kJ/kg, find the mean effective pressure.a) 884.3 kPab) 848.3 kPac) 488.3 kPad) 838.4 kPaProducer of Brilliant Mechanical Engineers in the CALABARZONEngineering Review Center# 2 Alvaran’s Apartment, Purok 7, Halang City of Calamba, LagunaTel/Fax # (049) 545 9828Cell # 0917 545 6548

JCSF Engineering Review CenterIPD PPD General Examination2Solution:()()()()%2.60%1001011%100r11e4.01kkth=⎥⎥⎦⎤⎢⎢⎣⎡−=⎥⎥⎦⎤⎢⎢⎣⎡−=−()()()kg/kJ3.6921501602.0qewAth===()()kg/m8699.01002733028708.0pRTv31=+==kg/m08699.0108699.0rvv3k12===kPa3.88408699.08699.03.692vvwvwp21Dm=−=−==8.A heater has an average temperature of coil is 80oC. Air enters at 29oC and leaves at 65oC. Find the by-pass factor.a) 0.50b) 0.3191c) 0.2941d) 0.7059Solution:2941.029806580BPF=−−=9.For an electric generator running at 15 revolution per second and 60 Hz, find the number of poles.a) 16 polesb) 10 polesc) 12 polesd) 8 polesSolution:()()poles8601560120Nf120p===10.A feed having 18 % moisture delivers 9000 kg/hr of dried product having 97 % solid. Find the moisture removed.a) 1646.34 kg/hrb) 1466.34 kg/hrc) 1664.34 kg/hrd) 1436.46 kg/hrSolution:()()2211MC1mMC1m−=−()()hr/kg34.6461018.0103.019000MC1MC1mm1221=−−=−−=hr/kg34.16460009334.64610mmm21=−=−=∆11.A thermal power plant generates 9000 kW and has also 400 kW power needed for auxiliaries. If heat generated by fuel is 15500 kW, what is the netthermal efficiency in%?

Upload your study docs or become a

Course Hero member to access this document

Upload your study docs or become a

Course Hero member to access this document

End of preview. Want to read all 144 pages?

Upload your study docs or become a

Course Hero member to access this document