AE BOARD REVIEWER Revised October 8, 2008
by Victorio L. Pasado SUBJECT 3 Rural Electrification, Agricultural Processing, Ag. Structures and Allied Subjects (34%)
INSTRUCTIONS: INSTRUCTIONS: Select the best answer. Shade the corresponding box of your answer in the answer sheet. Give only one answer for each question. Do not make any any unnecessary unnecessary marking marking in the answer answer sheet. sheet. 1. RURAL ELECTRIFICATION RENEWABLE ENERGY (GENERAL)
1. An international agreement which embodies the the Clean Development Mechanism or CDM. A. Geneva Convention
B. International Treaty C. Tokyo Protocol D. Kyoto Protocol
Answer: D 2. In what year will the Kyoto Protocol expire? A. 2011
B. 2012
C. 2015
D. 2020
C. RA 8559
D. RA 8435
C. RA 8559
D. RA 8435
Answer: A 3. Renewable Energy Act of 2008 is also known as A. RA 9367
B. RA 9513
Answer: B 4. Biofuels Act of 2006 is also known as A. RA 9367
B. RA 9513
Answer: A 5. What energy generating plant does not use turbine for power generation? A. Hydro
B. Geothermal
C. Ocean-thermal
D. Biogas plant
Answer: D 6. From the BiGSHOW acronym of renewable energy coverage, what “Bi” stands for? A. Biomass
B. Biofuel
C. Biomass and biofuel
D. Biodiesel
Answer: C 7. Aerogenerator, covered lagoon biodigester and minihydro energy projects are evaluated for financial feasibility. Only one feasible project can be funded. Each project needs PHP 30M investment. The financial internal rate of returns are 11%, 8% and 9%, respectively. Annual discount plus inflation rate is 12%. Which of the 3 projects shall be implemented? A. Aerogenerator B. Covered lagoon biodigester C. Minihydro D. None Answer: D (since (since all their their IRRs are less than the the discount discount plus inflation inflation rate) 8. An Ocean Thermal Energy Conversion (OTEC) project was evaluated for financial feasibility. At 12% annual discount rate, it has the following feasibility indicators: net present value of 2.5 billion pesos and internal rate of return of 60%. If annual discount rate drops to 10%, will the project still be feasible? A. No B. Yes C. Maybe D. Insufficient data to determine Answer: B (if it is feasible feasible at 12% discount discount rate, rate, the more it will will be feasible feasible at 10%)
ELECTRONICS, INSTRUMENTATION AND CONTROL
9. What part of solar module should be included such that solar charging is continuous at slower rate even when partially shaded by trees? A. Blocking diode B. Bypass diode
C. Shading diode
D. Lightning diode
Answer: B 10. What diode is needed as protection against lightning in solar installations? A. Blocking diode
B. Bypass diode
C. Shading diode
D. Lightning diode
Answer: A 11. What pin is common in integrated circuits (ICs). A. +12 Vdc input
B. +5 Vdc output
C. Ground
D. Binary output
Answer: C 12. A kind of IC included as an important part of electronic instruments for gathering speed, velocity and discharge real-time data. A. Voltage reducer
B. Timer
C. Sensor
D. Variable resistor
Answer: B 13. Which one is an integrated circuit (IC) used in instrumentation and control? A. TD 8062
B. ES 8813
C. CQ 556
D. LM 333
Answer: D 14. Which DC voltage is best for remote instrumentation? A. 5, 7 or 9 Vdc
B. 5 Vdc
C. 7 Vdc
D. 9 Vdc
Answer: A 15. Transmission of data to a remote line-of-sight point is best done using A. Fiber optics
B. Fax
C. E-mail
D. Radio frequency
Answer: D 16. To automate control of irrigation dam gates, what switch is useful in the instrumentation? A. Automatic transfer switch
B. Pressure switch
C. Power switch D. Time switch
Answer: A 17. A switch for automatic starting of pumps with sealed water tank in drip irrigation systems. A. Automatic transfer switch
B. Pressure switch C. Power switch
Answer: B
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D. Time switch
WIND POWER
18. What part of an aerogenerator exceeding 100 kw capacity is responsible in converting rotational movement to electricity? A. Alternator
B. Turbine
C. Rotor
D. Governor
Answer: A
19. The component of force used to rotate the rotor in multi-bladed windmills. A. Drag force
B. Lift force
C. Side force
D. Drop force
Answer: B
20. The component of force used to rotate the rotor in savonius windmills. A. Drag force
B. Lift force
C. Side force
D. Drop force
Answer: A
21. What type of pump is appropriate for multi-bladed windmills? A. Hydraulic
B. Diaphragm
C. Pneumatic
D. Reciprocating
Answer: D
22. What efficiency can exceed 100% while the windmill is in operation? A. Transmission
B. Volumetric
C. Rotor
D. Crank
Answer: B 23. A wind energy resource located about 10-16 km from Earth surface with velocity over 150 kph A. Terrestrial wind
B. Extra-terrestrial wind
C. High wind
D. Jet stream
Answer: D 24. Part of multi-bladed wind pump which is responsible in converting rotational movement to reciprocating action. A. Rotor
B. Reciprocating pump
C. Connecting rod
D. Crank arm
Answer: C 25. Which type of multi-bladed wind pump tail is more effective for windy areas? A. Ecliptic
B. Hinged side vane
Answer: B
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C. Manual folding
D. No tail
26. In big wind farm projects, which should be done first? A. Rotor
B. Transmission
C. Wind velocity measurement
D. Energy demand survey
Answer: C
27. In multi-bladed wind mill fabrication, what should be done first? A. Rotor blade
B. Rotor frame
C. Jig
D. Tower
Answer: C
28. To increase water displacement volume in wind mills, what part should be increased? A. Connecting rod length
B. Rotor diameter
C. Well diameter
D. Crank arm
Answer: D 29. To have a tip speed ratio of 1:1 in windmills, what should be the average rotor blade twist angle in degrees? A. 75
B. 60
C. 45
D. 30
Answer: C 30. If typical overall efficiency of multi-bladed windmills is 8-16%, what is the typical overall efficiency of manufactured aerogenerators or electricity generating windmills? A. 90-95%
B. 18-21%
C. 15-17%
D. 7-10%
Answer: A 31. If a wind mill rotor has a tip-speed ratio of 1:1, what windspeed is required for its rotor tip to move at 3.3 m/s? A. 1 m/s
B. 1 ft/s
C. 3.3 m/s
D. 3.3 ft/s
Answer: C Solution: Windspeed = tip speed, since tip-speed ratio is 1:1 = 3.3 m/s 32. An 4-bladed windpump with 7 meters rotor diameter and 45 degrees twist angle is to be modified due to insufficient starting torque. What should be do ne? A. Increase twist angle B. Increase blades C. Decrease blades
Answer: B (since increasing blades increases torque)
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D. Decrease twist angle
33. A windpump having 8 meters rotor diameter, 6 cm pump diameter and 2.2 cm crank arm is to be modified due to low volumetric efficiency. What should be done? A. Enlarge rotor
B. Reduce rotor
C. Enlarge pump diameter D. Elongate crank arm
Answer: D (Note: Elongating crank arm increases pump stroke and volumetric efficiency)
34. A 3-bladed 50-meter tall aerogenerator with 25 meters rotor radius designed for 6.2 m/s wind can’t rotate. Average windspeed at rotor center is 6 m/s. Which part needs to be increased? A. Number of blades
B. Rotor radius
C. Tower height
D. Crank arm
Answer: C (Note: Windspeed is higher at higher elevation; increasing rotor radius will severely affect twist angle of entire blade & tip-speed ratio; aerogenerators have no crank arm)
CONVENTIONAL ENERGY
35. What is the electrical energy consumption of a 30-kw vermicast production shredder plugged in a 240-volt source if it requires 1 hour to shred 2 tonnes of farm waste? A. 0.02 kwh/kg
B. 0.015 kwh/kg
C. 0.06 kwh/kg
Answer: B Solution: E c = PcT o / W i = 30 kw (1 h) / 2,000 kg = 0.015 kwh/kg
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D. 0.08 kwh/kg
SOLAR POWER
36. Battery appropriate for slow charging and slow discharging energy systems? A. Maintenance-free battery
B. Automotive battery C. NiCad Battery D. Solar battery
Answer: D 37. Kind of battery useful in solar home systems. A. Sealed lead-acid battery B. Automotive battery C. All lead-acid batteries C. Solar battery
Answer: C 38. Photovoltaic conductor material used in manufacturing solar modules. A. Silicon
B. Boron
C. Silicon with little boron
D. Equal silicon and boron
Answer: C 39. During a clear sky noontime in the Philippines, what is the possible voltage reading of solar pump without battery when electrical load is in switched on? A. 11-13 V Answer: C
B. 14-15 V
C. 16-19 V
D. 20-22 V
40. During a clear sky noontime in the Philippines, what is the possible voltage reading of solar battery charger when no battery is being charged? A. 11-13 V
B. 14-15 V
C. 16-19 V
D. 20-22 V
Answer: D 41. During 8:00 P.M. in the Philippines, what is the possible system voltage reading of a solar home system when all electrical loads are switched on? A. 11-13 V
B. 14-15 V
C. 16-19 V
D. 20-22 V
Answer: A 42. During solar panel installation, which positive polarity wire should be connected last to the battery control unit (BCU)? A. Solar module B. Battery Answer: B
C. Load
D. Monitor
43. When a bamboo shades half of solar module, which condition is true? A. Zero voltage Answer: C
B. Low voltage
C. Low amperage
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D. Zero amperage
HYDRO POWER
44. How do you classify a 260 kw hydro power plant? A. Microhydro
B. Small hydro
C. Minihydro
D. Big hydro
Answer: C 45. Using Philippine classification, specify the maximum power rating for microhydro? A. 100 kw
B. 75 kw
C. 50 kw
D. 25 kw
Answer: A
GEOTHERMAL ENERGY
46. The geothermal power system resembles in principle to a A. Hot air balloon
B. Gas pump
C. Jet propulsion
D. Kettle
Answer: D 47. Which stage comes first in a geothermal power plant development? A. Drilling
B. Geophysical survey
C. Energy demand survey
D. Chemical test
Answer: B 48. Rotating part of a geothermal power plant which moves the generator. A. Rotor
B. Rotator
C. Motor
D. Turbine
Answer: D
OCEAN ENERGY
49. The Ocean Thermal Energy Conversion (OTEC) operating principle resembles a A. Refrigerator
B. Gasoline engine
C. Hydro power plant D. Water tank
Answer: A 50. In an Ocean Thermal Energy Conversion (OTEC) system, what causes OTEC fluid to flow and rotate the turbine? A. Bouyancy
B. Fluid pressure
C. Underwater current
D. Temperature difference
Answer: D 51. Which one is not a form of ocean energy. A. Wave
B. Tidal
C. Transtidal
Answer: C
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D. Thermal
2. AGRICULTURAL PROCESSING
52. In the factory, bottling of virgin coconut oil prints batch numbers. What is the main purpose of batch numbers? A. Serial number Answer: C
B. Bottle identification
C. Product recall
D. Expiry indicator
53. Which one is not a part of a vertical feed mixer? A. Screw
B. Hopper
C. Conveyor
D. Discharge chute
Answer: C 54. Feed mixers evaluated to have 10-15% mixing coefficient of variation is rated as A. Very good
B. Good
C. Fair
D. Poor
Answer: B
55. Based on standards, the minimum stripping efficiency of the mechanized stripping machine shall be A. 90%
B. 85%
C. 80%
D. 70%
Answer: C
56. A 2.8-tonne capacity Jatropha oil expeller was loaded full with dried Jatropha seeds in 3 minutes. It produced 900 kg of crude oil in 2 hours. What is its crude oil production rate? A. 300 kg/h
B. 450 kg/h
C. 600 kg/h
D. 300 kg/min
Answer: B Solution: Poil = Weight of crude oil collected / Total time = 900 kg /2 h = 450 kg/h 57. A Jatropha oil expeller was loaded with 2.2 tonnes dried Jatropha seeds. It produced 600 kg of crude oil in 4 hours. What is its Jatropha cake production rate? A. 700 kg/h
B. 500 kg/h
C. 400 kg/h
Answer: C Solution: Pcake = Weight of resulting Jatropha cake produced / Total time = (2,200 kg seed - 600 kg oil) /4 h = 400 kg/h
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D. 300 kg/h
58. A 21-tonne capacity coconut oil expeller was loaded full with grated copra. It produced 7,000 kg of crude oil in 20 hours. What is the copra cake production rate of the machine at 95% cake collection efficiency? A. 700 kg/h
B. 665 kg/h
C. 588 kg/h
D. 885 kg/h
Answer: B Solution: Pcake = [(Wt. of copra input - Wt. of crude oil collected )/ Total time] x Eff = [(21,000 kg - 7,000 kg) /20 h] x 0.95 = 665 kg/h
59. How many tonnes of agricultural waste is needed annually to optimally operate a 25-ampere 5-kw vermicast production shredder having a capacity of 0.2 tonne of waste per hour? It optimally operates 16 hours daily during the 3-month peak sunny months and 8 h/day at 26 days/month for the rest of the year. A. 3312
B. 662
C. 1440
D. 1872
Answer: B Solution: Wt = Input Rate x (Peak Operating Time + Lean Operating Time) = [0.2 tonne/h][ (16 h/d x 30 d/mo x 3 mo/yr)+ (8 h/d x 26 d/mo x 9 mos/yr)] = 662 tonnes /yr
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3. AGRICULTURAL BUILDINGS AND STRUCTURES
IRRIGATION STRUCTURES
60. What is the standard diameter of both vertical and horizontal reinforcing bars in open channel construction? A. 16 mm
B. 12 mm
C. 10 mm
D. 8 mm
Answer: C 61. What class of concrete mix should be used in open channel construction? A. Class AA
B. Class A
C. Class B
D. Class C
Answer: B 62. What is the standard spacing between vertical bars in open channel construction? A. 20 cm
B. 25 cm
C. 30 cm
D. 50 cm
Answer: A 63. What is the standard concrete wall thickness of lateral trapezoidal open channel in open channel design? A. 5 cm
B. 10 cm
C. 12 cm
D. 15 cm
Answer: D 64. The appropriate gage number of galvanized iron (GI) tie wire for open channel construction. A. 10
B. 12
C. 16
D. 18
Answer: C 65. When using class A, B or C concrete mix, how many cubic meters of sand should be mixed to produce one cubic meter concrete? A. 0.25
B. 1.0
C. 0.75
D. 0.50
Answer: D
66. How many 40-kg bags of cement are needed per cubic meter concrete in standard (Class A) open channel construction? A. 6
B. 7.5
C. 9
Answer: C
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D. 12
67. In open channel construction, how many 40-kg bags of cement are needed for a 20-km lateral channel if it requires 0.6 cubic meter concrete per linear meter? Use 5% safety factor. A. 108,000
B. 114,300
C. 180,000
D. 113,400
Answer: D Solution: Bags = Safety factor x Bags cement/cu.m. concrete x Concrete volume/m x m length = 1.05 x 9 bags/cu.m. x 0.6 cu.m/m x 20,000 m = 113,400 bags
68. How many truck loads of sand are needed for 50-km main irrigation canal requiring 3.5 cubic meters concrete per linear meter? 1 truck load is 2.5 cubic meters. Use 5% safety factor. A. 36,750
B. 35,000
C. 36,570
D. 53,000
Answer: A Solution: Truck loads = Safety factor x Cu.m. sand/cu.m. concrete x Trucks/cu.m. x Concrete volume = 1.05 x 0.5 cu.m./cu.m. x 1 truck load/2.5 cu.m. x (3.5 cu.m/m x 50,000 m) = 36,750 truck loads
69. Estimate the truck loads of gravel needed for an 8-km main irrigation canal requiring 4 cubic meters concrete per linear meter. 1 truck load is 2.5 cubic meters. Use 10% safety factor. A. 12,800
B. 18,200
C. 14,080
D. 14,800
Answer: C Solution: Truck loads = Safety factor x Cu.m. gravel/cu.m. concrete x Trucks/cu.m. x Concrete volume = 1.1 x 1 cu.m./cu.m. x 1 truck load/2.5 cu.m. x (4 cu.m/m x 8,000 m) = 14,080 truck loads
70. How much should be budgeted for cement for 20-km irrigation canal if it requires half cubic meter concrete per linear meter and cement costs Php210/bag? Use 5% safety factor. A. Php 18,900,000
B. Php 19,845,000
C. Php 19,800,000
D. Php 18,945,000
Answer: B Solution: Budget = Safety factor x Bags cement/cu.m. concrete x Concrete volume x Unit Cost = 1.05 x 9 bags/cu.m. x (0.5 cu.m/m x 20,000 m) x Php 210 = Php 19,845,000
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71. Give cement budget estimate for 10-km canal requiring 2/3 cubic meter concrete per linear meter. Cement costs Php200/bag while transport costs Php 10/bag. Use 5% safety factor. A. Php 13,236,615
B. Php 12,606,300
C. Php 12,300,606
D. Php 13,615,236
Answer: A Solution: Budget = Safety factor x Bags cement/cu.m. concrete x Concrete volume x Unit Cost = 1.05 x 9 bags/cu.m. x (0.667 cu.m/m x 10,000 m) x (Php 200 + Php 10) = Php 13,236,615 72. A gravity dam weighing 75,000 tonnes is to be constructed with length along dam axis of 1 km and base of 100 meters. What should be the minimum soil bearing stress? Use factor of safety against sinking of 2. A. 1.5 tonnes/sq.m.
B. 0.75 tonnes/sq.m. C. 7.5 tonnes/sq.m.
D. 5.1 tonnes/sq.m.
Answer: A Solution: Sinking Factor of safety = Min. defensive bearing stress/Offensive bearing stress Min. def. stress = Sinking FS x Offensive Stress, Offensive stress = Weight/Area = 2 x (75,000 tonnes / (1,000 m x 100 m) = 1.5 tonnes/square meter 73. A 2-meter thick trapezoidal section of a concrete dam has resisting moment about the dam toe of 350,000 tonne-meters. The water exerts 4,050 tonnes horizontally at 30 meters above the dam toe. What is the factor of safety against overturning? A. 8.22
B. 1.80
C. 2.88
D. 2.08
Answer: C Solution: Overturing Factor of Safety = Resisting moment/Overturning moment = 350,000 /(4050 x 30) = 2.88 74. A concrete dam with 60,000 sq.m. submerged vertical upstream wall is to be constructed against a 546 tonnes/sq.m. average water pressure. Coefficient of friction at dam base is 0.8. What should be the minimum dam weight? Use factor of safety against sliding of 2. A. 65,520,000 tonnes B. 81,900,000 tonnes C. 65,520 tonnes D. 81,900 tonnes
Answer: B Solution: SlidingFactor of Safety = Min. defensive horizontal force/Offensive horizontal force Min. defensive force = Coef. of friction x Weight = FS x Offensive force Weight = FS x Offensive force / Coef. of friction Weight = 2 x (546 tonnes/sq.m. x 60,000 sq.m.) / 0.8 Weight = 81,900,000 tonnes
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4. WASTE MGT. & CLEAN DEVELOPMENT MECHANISM (CDM)
75. Value of fee to project owners from Clean Development Mechanism (CDM) fund for carbon emission reduction projects. A. Emission value B. Carbon credit value C. Carbon trading value D. Carbon sequestration
Answer: B 76. What is the acronym for the Inter-Governmental Panel for Climate Change? A. IGPFCC
B. IGPCC
C. IPCC
D. IPFCC
Answer: C 77. Best type of biogas plant for large-scale animal farms having low solid content of e ffluents. A. Fixed dome
B. Floating type
C. Tube-bag
D. Covered lagoon
Answer: D 78. Kind of plastic sheet for constructing balloon and bed lining in covered lagoon biogas plants. A. Acetate C. Linear low density polyethylene (LLDPE)
B. Polyvinyl Chloride (PVC) D. High density polyethylene (HDPE)
Answer: D 79. In the environment, by how many times is methane destructive than carbon dioxide? A. 2 times
B. 21 times
C. 10 times
D. 16 times
Answer: B 80. The toxic gaseous by-product of geothermal power plants that is trace in biogas. A. Carbon monoxide
B. Hydrogen sulfate C. Hydrogen sulfide D. Sulfuric acid
Answer: C 81. In covered lagoon biodigester where solids is less than 3%, what is approximate methane content in biogas? A. 40%
B. 50%
C. 60%
D. 70%
Answer: D 82. If water-manure ratio is 1:1, what is the approximate methane content of biogas? A. 40%
B. 60%
C. 70%
D. 50%
Answer: B 83. The minimum methane content of biogas such that biogas-fueled generators will run. A. 50%
B. 85%
C. 65%
Answer: C
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D. 75%
84. Determine the daily biogas consumption in cubic meters of an industrial boiler using 5 units of 50-cm gas burner 8 hours a day. The consumption of each gas burner is 1.2 cu.m./hour. A. 48
B. 84
C. 40
D. 80
Answer: A Solution: C = NBT where C= Consumption, N = No. of units, B = biogas consumption of device, T = Time C = (5 units)( 1.2 m3/hr)(8 hrs) = 48 m3
85. Estimate the biogas production in cubic meters per day from a large balloon type digester using 1:1 water-manure ratio. The source farm has 2,000 heads of porkers of mixed ages. Use a retention period of 30 days. The mean daily manure production of porkers is 2.2 kg/head while the specific gas production for 30-day manure retention period is 0.063 m3/kg. A. 4,400
B. 126
C. 162
D. 277
Answer: D Solution: P = NMG where P = biogas production potential, N = No.of heads, M = manure production, G = Specific gas production of the manure for a specific retention period 3 P = (2000 heads)(2.2 kg/head)(0.063 m /kg) = 277.2 m3
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86. How many heads of breeding cattle are needed as source of manure to generate 85 m3 of biogas a day if the retention period is 25 days and water-manure ratio is 1:1. The mean daily manure production of breeding cattle is 13 kg/head while its specific gas production for 25day manure retention period is half of that of chicken dung. A. 33
B. 7
C. 218
D. 34
Answer: C Solution: N = P/(MG) where N = No. of heads, C = biogas production, M = manure production, G = Specific gas production of the manure for a specific retention period G = 0.5 x G for chicken dung at 25-day retention period = 0.5 x 0.06 m3/kg = 0.03 m3/kg 3 3 C = (85 m )/[(13 kg/head)(0.03 m /kg)] = 217.9 heads, to avoid gas shortage round up to 193 heads
87. When approved as Clean Development Mechanism (CDM) project, how much will the project owner of a new covered lagoon biodigester receive annually from CDM fund for the first 10 years if the digester produces 7,000 tonnes of methane plus 3,000 tonnes of carbon dioxide annually. Assume current carbon credit costs US$12 per tonne of carbon equivalent. A. US$ 1,800,000
B. US$ 120,000
C. US$ 1,200,000
D. US$ 204,000
Answer: A Solution: Considering that methane is 21 times more destructive than carbon,
Amount = Carbon cost per tonne x [(tonnes carbon/year + 21 (tonnes of methane/year)] = US$ 12 [3,000 + 21(7,000)] = US$ 1,800,000/year
REFERENCES:
1. 2. 3. 4. 5. 6.
Philippine Agricultural Engineering Standards (PAES), Vols. 1-8 Biogas Plant Design by Arthur It. Tambong, 1992 Fundamentals of Environmental Science by G. C. Catchillar, 2008 Philippine Agricultural Engineering Journal, Vol. XXX (2) Renewable Energy Journal, various issues & authors Manual for Micro-Hydropower Development, DOE and JICA, 2004
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