ABE Board Exam Reviewer Part III PDF 2022

[email protected] 05 Sep 2022 ABE BOARD EXAM REVIEWER Part III Arthur It. Tambong, FPSAE [email protected] 05...

[email protected] 05 Sep 2022 ABE BOARD EXAM REVIEWER Part III Arthur It. Tambong, FPSAE [email protected] 05 Sep 2022 ABE Board Exam Reviewer Part III Copyright © 2022 by Arthur It. Tambong, FPSAE All rights reserved. Keeping this ebook in any form without proof of personal purchase shall be considered a violation of the intellectual property right of the author by both the ebook keeper and the buyer associated with the email address printed at the top of pages. GENERAL COVERAGE Rural Electrification, Agricultural Processing, Agricultural Structures and Allied Subjects SPECIFIC COVERAGE BASED ON PRC TABLE OF SPECIFICATIONS I. Rural Electrification (25%) – Page 3 II. Agricultural Processing (30%) – Page 15 III. Agricultural Buildings and Structures (35%) – Page 20 IV. Waste Management (10%) – Page 35 ESTIMATED COMPOSITION OF EXAMINATION QUESTIONS BY DEGREE OF DIFFICULTY Easy – 40% Moderate – 30% Difficult – 30% 2 [email protected] 05 Sep 2022 BOARD REVIEW QUESTIONS INSTRUCTIONS: Select the best answer. Shade the corresponding box of your answer on your answer sheet (provided during the exam). Give only one answer for each question. Do not make any unnecessary marking in your answer sheet. I. Rural Electrification (25%) A. General Knowledge Easy Questions 1. States that the voltage or potential difference between two points is directly proportional to the current or electricity passing through the resistance and directly proportional to the resistance of the circuit. A. Ohm's law B. Voltage law C. Amperage law D. Electrical law Answer: A 2. Based on the 2009 Philippine Electrical Code, what is the minimum conductor size in mm 2 for a voltage rating of 0-2,000 volts when using copper wire? A. 2 B. 6 C. 8 D. 10 Answer: A 3. A farmhouse requires a minimum conductor size of 2 mm 2 which is equivalent to AWG ____. A. 10 B. 12 C. 14 D. 16 Answer: C (AWG 14 has 2.08 mm2 conductor size, AWG 16 should not be used in houses. Except for the drop wire, the common household wires are AWG nos. 10, 12 & 14.) 4. Which electrical wire in the list below has the biggest cross-sectional area? A. AWG 14 B. AWG 12 C. AWG 10 D. AWG 8 Answer: D 3 [email protected] 05 Sep 2022 5. Which type of electrical wire has a maximum operating temperature of 90 oC? A. THW B. RHW C. THHN D. THWN Answer: C 6. Based on the Phil. Electrical Code, what is the minimum conductor size in mm 2 for a voltage rating of 2,001-8,000 volts when using copper, aluminum or copper-clad aluminum wire? A. 2 B. 6 C. 8 D. 10 Answer: 8 7. If V is voltage, I is current and P is power, according to Ohm's law, V is equal to _____. A. P/I B. IR C. I/P D. I2R Answer: B 8. Ohm's law is applicable to _____. A. DC only B. AC only C. Both DC and AC D. DC but not AC Answer: C 9. Ohm's law applies to both AC and DC circuits as long as mutual _________ of the circuit is considered. A. Resistance B. Capacitance C. Conductance D. Inductance Answer: D 10. The resistivity of annealed copper in ohm meters at 20 oC. A. 1.72 x 10-8 B. 1.59 x 10-8 C. 1.68 x 10-8 D. 2.65 x 10-8 Answer: A 11. The resistance of a certain length of wire can be obtained by multiplying its ________ with its length and dividing the resulting product by the cross-sectional area of the wire. A. Conductivity B. Resistivity C. Malleability D. Ductility Answer: B 4 [email protected] 05 Sep 2022 12. A farmstead has its farthest load located 350 linear meters from a single phase power source. What length of the wire in meters should be used in the voltage loss computation? A. 350 B. 600 C. 700 D. 500 Answer: C 13. In connecting electricity from a post to a farmhouse, a ______ wire is needed. A. Transmission B. Drop C. Automotive D. Electrical Answer: B 14. The minimum wire size for a farmhouse drop wire. A. AWG 4 B. AWG 6 C. AWG 8 D. AWG 10 Answer: B 15. A solar powered slaughterhouse uses electrical stunning gun to make the animals insensible to pain before the slaughter. What should be the voltage of the stunning gun? A. 12 Vdc B. 24 Vdc C. 220 Vdc D. 220 Vac Answer: D 16. Based on PAES 419:2000, the recommended lighting intensity in lux (lumen/m 2) for fruit and vegetable processing plant are: 100 for outside the building, 200 for general indoor locations, and ___ for working tables. A. 300 B. 500 C. 400 D. 600 Answer: B 17. A poultry layer area requires a brightness of 1,600 lumens. What is the wattage of a daylight- color LED bulb that shall be used? A. 100 B. 80 C. 75 D. 60 Answer: A (since a 100-watt daylight-color LED bulb brightens by about 1,600 lumens) 5 [email protected] 05 Sep 2022 Moderate Questions Before answering questions, first memorize the formulas in the Ohm’s law formula wheel. Such that it is visible to you while answering questions, write a small version of this in the blank space of your questionnaire unless instructed otherwise, but never on your answer sheet since you are not allowed to make any unnecessary marking in your answer sheet. Normally, your questionnaire also serves as your scratch paper. With this formula wheel written on your questionnaire, you can quickly make solutions by directly using a calculator. Time is very limited in board examinations. The formula wheel has inner and outer wheels and divided in four quadrants. The inner wheel contains the unknown variables: Amperage I in amperes in the first quadrant, Resistance R in ohms in the second quadrant, Voltage V in volts in the third quadrant, and Power P in watts in the fourth quadrant. The outer wheel indicates the corresponding 3 possible formulas for each unknown in the inner wheel. The specific formula to be used depends on the known values. For example, if I and R are known and V needs to be determined, then you can use the formula V=IR in the third quadrant. In some cases, one or more values of variables in the formulas need to be computed first in order to be known. For example, if current I is asked in the problem given the voltage V plus the length, cross-sectional area and temperature of the wire. To solve this using the first quadrant, compute for the resistance R first using the length, cross-sectional area and temperature of the wire. Then, use I=V/R to determine the current I. Alternatively, you can determine the current I using any other quadrants. To solve complex problems, you may need to use one or more quadrants. Figure 1. The Ohm’s law formula wheel (source: Gigacalculator.com, 2022) 6 [email protected] 05 Sep 2022 18. What is the voltage needed to light a 1-ampere LED bulb having a resistance of 220 ohms? A. 1 volt B. 220 volts C. 2 volts D. 110 volts Answer: B Solution: Applying the formula V=IR in the third quadrant of the formula wheel, V = IxR = (1 A) x (220 ohms) = 220 volts 19. How many amperes will pass through a circuit having ten 22-watt LED bulbs if the source is 220 volts? A. 1 watt B. 220 watts C. 2 watts D. 110 watts Answer: A Solution: Applying the formula I=P/V in the fourth quadrant of the formula wheel, I = P/V = (10 x 22 w) / (220 v) = 1 Amp 20. What is the electrical energy consumption of a 15-kw vermin cast production shredder plugged in a 220-volt source if it requires 2 hours to shred 1.5 tonnes of farm waste? A. 0.02 kwh/kg B. 0.04 kwh/kg C. 0.06 kwh/kg D. 0.08 kwh/kg Answer: A Solution: Ec = PcTo / Wi = 15 kw (2 h) / 1,500 kg = 0.02 kwh/kg 7 [email protected] 05 Sep 2022 Difficult Questions 21. Solid annealed copper has a resistivity of 1.72 x 10-8 ohm-meter at 20 oC. What is the resistance in ohm-meter per linear meter of AWG 10 solid annealed copper wire having a diameter of 2.588 mm? A. 3.27x10-3 ohms B. 2.6x10-3 ohms C. 5.5x10-3 ohms D. 3.72x10-3 ohms Answer: A Solution: Determining the cross-sectional are of the wire in square meters, A = 3.1416 x (Diameter)2 / 4 = 3.1416 x (2.588 mm x 1 m/1000 mm)2 / 4 = 5.26 x 10-6 m2 Determining the resistance of AWG 10 solid annealed copper wire per linear meter, R = Resistivity x Length / Cross-sectional area = (1.72 x 10-8 ohm-m) x (1 m) / (5.26 x 10-6 m2) = 3.27 x 10-3 ohms 22. A 240-volt industrial incubator uses a pair of 25-meter 7-strand AWG 10 copper wire having a resistance of 3.87x10-3 ohm per linear meter at 65 oC. The heating load of the incubator is composed of twelve 100-watt heating coils. What is the expected current in the main wire? A. 30 A B. 3 A C. 0.03 A D. 0.3 A Answer: C Solution: Determining coil resistance R1 using the formula R=V2/P in the second quadrant, R1 = No. of coils x V2/P = 12 x (240 v)2 / 100 w = 6,912 ohms Determining total resistance R, R = [No. of wires x (Resistance per unit length x Length)] + Coil resistance = [2 wires x (3.87x10-3 ohm/m x 25 m)] + 6,912 ohms = 0.19 ohms + 6,912 ohms = 6,912.19 ohms Determining the current I using the formula I=V/R in the first quadrant of the formula wheel, I = V/R = 240 volts / 6,912.19 ohms = 0.03 amp. 8 [email protected] 05 Sep 2022 B. Application of Renewable Energy in Rural Electrification Easy Questions 1. In off-grid farmhouse electrification, which one has the lowest operation and maintenance cost? A. Solar Home System B. Hydro power plant C. Diesel generator D. Grid extension Answer: A 2. Which one has the highest operation and maintenance cost? A. Solar Home System B. Hydro power plant C. Diesel generator D. Grid extension Answer: C 3. In off-grid barangay electrification located 3 kilometers from the electricity grid, which one is recommended? A. Solar Home System B. Hydro power plant C. Diesel generator D. Grid extension Answer: D 4. Which electricity source has no greenhouse gas emission? A. Solar Home System B. Hydro power plant C. Diesel generator D. Grid extension Answer: A 5. Which electricity source has the highest greenhouse gas emission? A. Solar Home System B. Hydro power plant C. Diesel generator D. Grid extension Answer: C 6. To minimize power loss, which equipment is needed to transform DC electricity from a centralized solar power plant into AC electricity before transmitting it to distributed 220-volt farmstead electrical devices? 9 [email protected] 05 Sep 2022 A. Inverter B. Transformer C. Converter D. Transmitter Answer: A Moderate Questions 7. A 950-kw cassava flour processing plant is to be powered using hydro. Which electricity source will you use recommend? A. Picohydro B. Microhydro C. Minihydro D. Small hydro Answer: C (Under the Philippine classification, minihydro is over 100 kw up to 10 mw) 8. A 3 hectare hillside farm is to be energized. It is 20 meters below a river having a dependable summer discharge of 50 liters/second. Which electricity source will you use recommend? A. Picohydro B. Microhydro C. Minihydro D. Small hydro Answer: B (Picohydro is up to 5 kw only while mini and small hydros are oversized) 9. The 1-kw lighting of a farmstead is to be energized using hydropower. It is 10 meters below a creek having a dependable summer discharge of 5 liters/second. Which hydropower will you recommend for development? A. Picohydro B. Microhydro C. Minihydro D. Small hydro Answer: A (since power requirement is less than 5 kw, picohydro is recommended) 10. An 8-bladed horizontal axis windmill with 12-meter tall tower has 2.5-m diameter rotor. Estimate the power output in watts using the rule of thumb formula. Average windspeed in the site is 3.2 m/s. A. 61 B. 17 C. 71 D. 16 Answer: D Solution: Using the rule of thumb formula, this takes efficiency into consideration P = 0.1 AV3, P is power output in watts, A is rotor area in m2, V is windspeed in m/s = 0.1 [3.14 x (2.5 m)2/4] [3.2 m/s] 3 = 16.08 watts 10 [email protected] 05 Sep 2022 11. How many households can be powered by a minihydro having a power generation output of 500 kw if an average household consumes 1 kw and power loss is 15%? A. 245 B. 425 C. 452 D. 524 Answer: B Solution: No. of households = (Power Output – Power Loss) / Average household consumption = (500 kw – 0.15 (500 kw) / 1 kw = 425 households 12. A battery bank of a centralized solar power generator needs to store energy in a 48-volt DC system to power a cassava processing plant. If each battery is 12 volts, how many batteries are there in series? A. 4 B. 5 C. 2 D. 15 Answer: A Solution: No. of batteries in series = System Voltage / Battery nominal voltage = 48 volts / 12 volts = 4 batteries in series 13. An off-grid tomato processing plant has 48-volt output battery bank composed of 60 units of 12-volt automotive batteries. How many batteries are there in parallel? A. 4 B. 5 C. 2 D. 15 Answer: D Solution: No. of batteries in series = System Voltage / Battery nominal voltage = 48 volts / 12 volts = 4 batteries in series No. of batteries in parallel = Total number of batteries / No. of batteries in series = 60 total batteries / 4 batteries in series = 15 batteries in parallel 11 [email protected] 05 Sep 2022 Difficult Questions 14. How kilowatts can be generated from a waterfall having a discharge of 1 m 3/s, reliable head of 100 meters during summers and system efficiency of 60%? A. 588 B. 598 C. 589 D. 859 Answer: C Solution: P = 9.81 QHE, P in kw, Q in m3/s, H in m, E in ratio = 9.81 (1 m3/s) (100 m) (0.6) = 588.6 kw 15. A hydropower resource with water outlet 95 meters high from ground surface has fluctuating discharge of 1.8 m3/s during summers and 3.5 m3/s during rainy months. How many megawatts can be generated at the powerhouse placed below the ground surface with the turbine water inlet 30 meters below ground level? Assume a reliable system efficiency of 60%. A. 1.32 B. 1.23 C. 2.13 D. 3.12 Answer: A Solution: Use the minimum discharge, include depth of turbine water inlet to the head. P = 9.81 QHE, P in kw, Q in m3/s, H in m, E in ratio = 9.81 (1.8 m3/s) (95 m + 30 m) (0.6) = 1,324 kw x 1 MW/1,000 kw = 1.32 MW 16. A centralized solar power plant with DC to AC inverter is used to electrify a farmstead using 75 watt-peak solar modules of the same brand. How many kilowatts-hours of energy in an average day of 5 hours sensible sunlight can be generated by 100 units of solar modules if inversion efficiency is 85%, module matching efficiency is 95% and transmission efficiency from modules to centralized battery bank is 95%? A. 28 B. 29 C. 30 D. 31 Answer: B Solution: P = No. of modules x Power rating x Sunlight hours x Inversion eff x Match eff x Trans. eff = 100 x 0.075 kw x 5 hours 0.85 x 0.95 x 0.95 = 28.77 kwh 12 [email protected] 05 Sep 2022 C. Electronics, Instrumentation and Control in Rural Electrification Easy Questions 1. The board used in Arduino open-source electronics platform based on easy-to-use hardware and software which is able to read inputs like light on a sensor, temperature reading, a finger on a button, or a Twitter message and can turn these inputs into outputs like activating a motor, turning on an LED, turning on a solenoid valve, or publishing something online. A. Microcontroller B. Integrated circuit C. Microchip D. Switch board Answer: A 2. An Arduino microcontroller is used to activate mist sprinkler system for 10 minutes every time the greenhouse temperature rises above a certain level. What device is best turned on by the microcontroller to start the mist sprinklers? A. Mist sprinkler B. Gate valve C. Solenoid valve D. Power switch Answer: C 3. The name given to Arduino code files which serve as instructions to the microcontroller. A. Program B. Sketch C. Control D. App Answer: B 4. Part of solar module needed such that solar charging is continuous at slower rate when partially shaded by trees. A. Blocking diode B. Bypass diode C. Shading diode D. Lightning diode Answer: B 5. A diode needed as protection against lightning in solar installations. A. Bypass diode B. Shading diode C. Blocking diode D. Lightning diode Answer: C 6. The common pin, made as the pair to other pins, in integrated circuits (ICs). 13 [email protected] 05 Sep 2022 A. +12 Vdc input B. +5 Vdc output C. Ground D. Binary output Answer: C 7. An integrated circuit (IC) included as an important part of electronic instrumentation for gathering speed and discharge real-time data. A. Voltage reducer B. Variable resistor C. Timer D. Sensor Answer: C 8. Which one is an integrated circuit (IC) used in instrumentation and control? A. ES 8813 B. LM 333 C. CQ 556 D. TD 8062 Answer: B 9. What voltage is appropriate in remote instrumentation? A. 5, 7 and 9 Vdc B. 7 Vdc C. 9 Vdc D. 5 Vdc Answer: A 10. Data transmission to a remote, unelectrified and line-of-sight point is best done through ___. A. Fiber optics B. Email C. Radio frequency D. Fax Answer: C 11. In automatic 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 12. Switch for automatic pump motor control of sealed water tanks in drip irrigation systems. A. Automatic transfer switch B. Pressure switch C. Power switch D. Time switch Answer: B 14 [email protected] 05 Sep 2022 II. Agricultural Processing (30%) Easy Questions 1. Under PAES 418:2002, washing of tomato is done by using ____% chlorox solution applied by dipping, spraying or wiping with a damp cloth then drying the fruit before packing. A. 0.5% B. 1% C. 1.5% D. 0% Answer: B 2. Based on PAES 419:2000, the recommended optimum stack height in meters for storage of both paddy and rice grains. A. 4.27 B. 4.57 C. 4.75 D. 5.47 Answer: A 3. What standard shall be followed in constructing large-scale poultry dressing/slaughtering plants? A. PAES 422-1:2012 B. PAES 422-2:2012 C. PAES 422:2012 D. PAES 422-3:2012 Answer: B 4. Based on PAES 419:2000, the recommended optimum stack height for storage of wheat, barley and maize grains. A. 4.27 B. 4.57 C. 4.75 D. 5.47 Answer: B 5. PAES 419:2000 requires that food grains stored in a warehouse for bagged storage are in the range of 12 to ____ % moisture content prior to storing. A. 12 B. 12.5 C. 13 D. 14 Answer: D 6. The Philippine standard for grading and classification of paddy and milled rice grains. 15 [email protected] 05 Sep 2022 A. PNS/BAFS 290:2019 B. PNS 42:2019 C. PNS 162:2015 D. PNS 194:2017 Answer: A 7. The Philippine standard for code of practice and postproduction of organic milled rice. A. PNS/BAFS 290:2019 B. PNS 42:2019 C. PNS 162:2015 D. PNS 194:2017 Answer: B 8. The Philippine standard for Maximum Residue Limits (MRLs) of pesticide residues in rice. A. PNS/BAFS 290:2019 B. PNS 42:2019 C. PNS 162:2015 D. PNS 194:2017 Answer: C 9. The Philippine general standard for contaminants and toxins in food and feed. A. PNS/BAFS 290:2019 B. PNS 42:2019 C. PNS 162:2015 D. PNS 194:2017 Answer: D 10. Industrial bottling of virgin coconut oil prints a batch number. What is the main purpose of this batch number? A. Product recall B. Bottle identification C. Expiry indicator D. Serial number Answer: A 11. Which one is not a part of a vertical feed mixer? A. Conveyor B. Hopper C. Discharge chute D. Screw Answer: A 12. A feed mixer tested to have mixing coefficient of variation of 10-15% is rated as _____. A. Poor B. Fair C. Very good D. Good 16 [email protected] 05 Sep 2022 Answer: D 13. As a standard, stripping efficiency of the mechanized stripping machine shall be at least A. 80% B. 70% C. 85% D. 90% Answer: A Moderate Questions 14. What is the percent moisture content in dry basis of a rice sample having 100 grams and 82 grams wet and dry weights? A. 18 B. 21 C. 22 D. 25 Answer: C Solution: MCdb = 100% x (Wet weight – Dry weight) / Dry weight = 100% x (100 gm – 82 gm) / 82 gm = 21.95% 15. What is the percent moisture content in wet basis of a corn sample having 100 grams and 82 grams wet and dry weights? A. 18 B. 21 C. 22 D. 25 Answer: A Solution: MCwb = 100% x (Wet weight – Dry weight) / Wet weight = 100% x (100 gm – 82 gm) / 100 gm = 18% 16. A dried palay sample was milled using a rubber roller laboratory rice mill. After milling, the weight of whole milled grains, broken milled grains, and hull were 25 g, 305 g and 170 g, respectively. The milled rice was classified as Class A. Determine the percent head rice. A. 4% B. 5% C. 6% D. 7% 17 [email protected] 05 Sep 2022 Answer: B Solution: Percent Head rice = 100% (Weight of whole grains) / Total weight = 100% (25 kg) / (25 g + 305 g +170 g) = 5% 17. A 3.1-tonne capacity Jatropha oil expeller was loaded full with dried Jatropha seeds in 4 minutes. It produced 1200 kg of crude oil in 3 hours. What is its crude oil production rate? A. 200 kg/min B. 400 kg/h C. 600 kg/h D. 600 kg/min Answer: B Solution: Poil = Weight of crude oil collected / Total time = 1,200 kg /3 h = 400 kg/h 18. A Jatropha oil expeller was loaded with 2.2 tonnes dried Jatropha seeds. It produced 700 kg of crude oil in 5 hours. What is its Jatropha cake production rate? A. 700 kg/h B. 500 kg/h C. 400 kg/h D. 300 kg/h Answer: D Solution: Pcake = Weight of resulting cake produced / Total time = (2,200 kg seed - 700 kg oil) /5 h = 300 kg/h 18 [email protected] 05 Sep 2022 Difficult Questions 19. A 21-tonne capacity coconut oil expeller was loaded full with grated copra. It produced 9,000 kg of crude oil in 12 hours. What is the copra cake production rate of the machine at 97% cake collection efficiency? A. 392 kg/h B. 600 kg/h C. 588 kg/h D. 970 kg/h Answer: D Solution: Pcake = [(Wt. of copra input - Wt. of crude oil collected )/ Total time] x Eff = [(21,000 kg - 9,000 kg) / 12 h] x 0.97 = 970 kg/h 20. How many tonnes of agricultural waste is needed annually to optimally operate a 27-ampere 9-kw vermi cast production shredder having a capacity of 0.27 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. 810 B. 512 C. 894 D. 521 Answer: C Solution: Wt = Input Rate x (Peak Operating Time + Lean Operating Time) = [0.27 tonne/h][ (16 h/d x 30 d/mo x 3 mo/yr)+ (8 h/d x 26 d/mo x 9 mos/yr)] = 894 tonnes /yr 19 [email protected] 05 Sep 2022 III. Agricultural Buildings and Structures (35%) A. General Knowledge Easy Questions 1. As prescribed in PAES 419:2000, in constructing the walls of a warehouse for bagged storage of grains, the wall should use _____ mm thick concrete hollow blocks with 12 mm diameter reinforcing bars at horizontal and vertical spacing of 600 mm. A. 100 B. 150 C. 200 D. 250 Answer: B 2. Known as the National Building Code of the Philippines. A. PD 1096 B. RA 1096 C. PD 1069 D. RA 1906 Answer: A 3. Type of the building that is made of steel, iron, concrete, or masonry construction. A. Type I B. Type II C. Type III D. Type IV Answer: D 4. PAES 419:2000 requires that a normal-temperature warehouse intended for storage of bagged grains shall have a minimum interior height between the beam and floor of ____ meters. A. 3 B. 4. C. 5 D. 6 Answer: D 5. Under PAES 418:2002, in constructing a primary processing plant for fresh fruit and vegetable, the windowsill shall be at least _____ m from the finished floor line. A. 0.5 B. 0.75 C. 1 D. 1.25 Answer: C 20 [email protected] 05 Sep 2022 6. Under PAES 418:2002, in constructing a primary processing plant for fresh fruit and vegetable, the doors shall have a minimum width of _____ m. A. 1 B. 1.5 C. 1.25 D. 1.75 Answer: B 7. Habitable rooms provided with artificial ventilation shall have ceiling heights of not less than ______ meters measured from the floor to the ceiling (PD 1096). A. 2.1 B. 2.4 C. 2.7 D. 2.8 Answer: B 8. Smallest dimension in centimeters of concrete hollow blocks in the Philippines. A. 10x20x40 B. 15x20x40 C. 20x20x40 D. 25x20x40 Answer: A 9. For buildings of more than one storey, the minimum ceiling height of the first storey shall be _____ meters and that for the second storey 2.40 meters and succeeding storeys shall have an unobstructed typical head-room clearance of not less than 2.10 meters above the finished floor (PD 1096). A. 2.1 B. 2.4 C. 2.7 D. 2.8 Answer: C 9. All buildings located in areas where there is no sanitary sewerage system shall dispose their sewage to imhoff tank or ___________ and subsurface absorption field (PD 1096). A. Imhoff tank B. Septic tank C. Waste tank D. Water tank Answer: B 10. A tank for sewage consisting of an upper or sedimentation chamber with sloping floor leading to slots through which the solids settle to the lower sludge-digestion chamber. A. Imhoff tank B. Septic tank C. Waste tank D. Water tank 21 [email protected] 05 Sep 2022 Answer: A 11. Based on the Building Code, when excavating near adjoining buildings the owners of adjoining buildings shall be notified in writing at least how many days before excavation? A. 10 B. 7 C. 15 D. 30 Answer: A 12. As provided in the Building Code, when curing concrete made from ordinary portland cement, the concrete shall be maintained above 10 degrees Celsius and in moist condition for the first how many days at least? A. 30 B. 10 C. 15 D. 7 Answer: D 13. When curing concrete made from high strength portland cement, what is the minimum curing time in days as provided in the Building Code? A. 1 B. 5 C. 3 D. 7 Answer: C 14. What percentage of concrete strength is reached at the end of the first week? A. 70% B. 50% C. 33% D. 80% Answer: A 15. The initial setting of concrete starts in the first how many hours after concrete mixing? A. 1-1.5 B. 4-5 C. 2-3 D. 6-7.5 Answer: C 16. Wood stick or board nailed horizontally at the stake which serves as the horizontal plane where the reference points of building measurements are established. 22 [email protected] 05 Sep 2022 A. Batter board B. Reference board C. Building reference D. Stake plane Answer: A 17. In building construction, which step comes next to checking building permit? A. Locating boundaries B. Staking C. Clearing D. Temporary fencing Answer: A 18. To establish an accurate 90-degree corner in a building layout, what will you use? A. 45 degrees triangle B. Carpenter’s square C. Whole plywood D. Carpenter’s level Answer: C 19. Material other than portland cement, aggregate, or water that is added to concrete to modify concrete properties. A. Proofer B. Admixture C. Refiner D. Additive Answer: B 20. What is the equivalent compressive strength of ordinary concrete in kg per square centimeter for 2,500 psi? A. 176 B. 1,136 C. 388 D. 5,500 Answer: A 21. To attain about 3,000 psi compressive strength in non-air entrained concrete, how many liters of water should be added per bag of cement? A. 27.6 B. 22 C. 25 D. 19 Answer: C 22. When using 0.75 inch nominal maximum size of coarse aggregate, what is the estimated percentage of air content by volume in concrete? 23 [email protected] 05 Sep 2022 A. 6-10 B. 4-8 C. 5-9 D. 3-6 Answer: B 23. When made of normal weight aggregate, what should be the maximum water-cement ratio of concrete that is intended to be watertight when exposed to fresh water? A. 0.44 B. 0.48 C. 0.42 D. 0.40 Answer: B 24. For a concrete agricultural structure made from normal weight aggregate and in contact with sea water, what should be the maximum water-cement ratio for it to be watertight? A. 0.48 B. 0.42 C. 0.44 D. 0.40 Answer: C 25. The weight in kilograms of a 6-meter long standard 10 mm diameter reinforcing bar. A. 1.3 B. 3.7 C. 2.2 D. 5.3 Answer: B 26. The cross-sectional area in square millimeters of a standard 16 mm diameter reinforcing bar. A. 201.1 B. 113.1 C. 314.2 D. 280.13 Answer: A 27. In a wall footing, the horizontal steel reinforcement is said to be normally adequate if steel cross sectional area relative to concrete cross sectional area is ________. A. 0.02-0.03% B. 0.4-0.5% C. 0.2-0.3% D. 1-2% Answer: C 28. What is the least number of longitudinal bars in a tied concrete column? A. 2 B. 4 C. 3 D. 6 24 [email protected] 05 Sep 2022 Answer: B 29. What is the minimum diameter of longitudinal bars in a tied concrete column? A. 8 mm B. 10 mm C. 16 mm D. 12 mm Answer: C 30. Based on ACI Code, what is the minimum diameter of lateral ties in a tied concrete column for 32 mm or smaller longitudinal bars? A. 6 mm B. 10 mm C. 8 mm D. 12 mm Answer: B 31. Based on ACI Code, what is the minimum diameter of lateral ties in a tied concrete column for 36 to 57 mm and bundled longitudinal bars? A. 6 mm B. 8 mm C. 12 mm D. 10 mm Answer: C 32. Based on ACI Code, the maximum spacing of lateral ties in a tied concrete column should not be more than _____ times the diameter of the longitudinal bars. A. 24 B. 16 C. 32 D. 48 Answer: B 33. Based on ACI Code, the maximum spacing of lateral ties in a tied concrete column should not be more than _____ times the diameter of the lateral ties. A. 16 B. 24 C. 48 D. 32 Answer: C 25 [email protected] 05 Sep 2022 Moderate Questions 34. Based on the standards of American Concrete Institute (ACI), what are the minimum width and minimum concrete depth, respectively, of a square independent column footing carrying 9 tonnes load if soil pressure is 2,000 psf? A. 4.67’, 10” B. 3.33’, 10” C. 5.75’, 12” D. 6.6’,13” Answer: B (Based on ACI Table of Safe Load for Square Independent Column Footing) 35. Using the standards of American Concrete Institute, specify the total number and size of horizontal reinforcing bars needed for a concrete square column footing of a farmhouse carrying 18 tonnes load if soil pressure is 2,000 psf and concrete compressive strength is 2,500 psi. A. 4 pcs.10 mm B. 8 pcs.10 mm C. 16 pcs.12 mm D. 8 pcs.12 mm Answer: C (Based on ACI Table of Safe Load for Square Independent Column Footing) Difficult Questions 36. Determine the lateral ties spacing for a concrete column of a farmhouse having 36 cm x 40 cm side dimension. It uses 22 mm longitudinal bars and 10 mm lateral ties. A. 30.2 cm B. 36.6 cm C. 35.2 cm D. 48.6 cm Answer: C Solution: Spacing based on longitudinal or vertical bar diameter, Sv Sv = 16 x vertical bar diameter = 16 x 2.2 cm = 35.2 cm Spacing based on lateral tie or horizontal bar diameter, Sh Sh = 48 x horizontal bar diameter = 48 x 1 cm = 48 cm Spacing based on side dimension of tied column, Ss Ss = shortest side dimension of column = 36 cm Lateral ties spacing = smallest of Sv, Sh and Ss = 35.2 cm 26 [email protected] 05 Sep 2022 B. Farm-to-Market Roads Easy Questions 1. Based on Farm-to-Market Road (FMR) standard, PAES 421:2009, if the slope of an FMR exceeds ___%, concrete-lined or masonry-lined ditch should be provided. A. 4% B. 5% C. 6% D. 7% Answer: A 2. Granular material of mineral composition such as sand, gravel, shell, crushed and uncrushed stone or lightweight materials. A. Aggregates B. Pebbles C. Crushed stones D. Granules Answer: A 3. The minimum carriageway of one-lane and two-lane farm-to-market roads, respectively, excluding the road shoulders, shall be ______. A. 3.5 and 7 m B. 3 and 6 m C. 2 and 4 m D. 2.5 and 5 m Answer: C 4. In lateral and sub-lateral irrigation canals where the available roadway width is 3 meters, the carriageway and shoulder, respectively, of the farm-to-market road shall be _______. A. 2.8 and 0.2 m B. 2 and 0.5 m C. 2.4 and 0.3 m D. 2 and 1 m Answer: B 5. In main irrigation canals where the available roadway width is 6 meters, the shoulder and carriageway, respectively, of the farm-to-market road shall be ______. A. 0.5 and 5 m B. 0.5 and 4.5 C. 1 and 4 m D. 1 and 5 m Answer: C 6. For gravel and bituminous farm-to-market roads, the minimum slope from the centerline towards the ditch shall be ______. 27 [email protected] 05 Sep 2022 A. 1% B. 2% C. 2.5% D. 3% Answer: D 7. For concrete farm-to-market roads, the maximum slope from the centerline towards the ditch shall be ______. A. 5% B. 3% C. 1.5% D. 2.5% Answer: C 8. For farm-to-market roads constructed along the main, lateral and sub-lateral irrigation canals, the run:rise side slope of the earth embankment shall be ______. A. 2:1 B. 1.5:1 C. 1:1 D. 0.5: 1 Answer: B 9. In farm-to-market roads, the minimum radius of curvature for flat, rolling and mountainous terrains, respectively, shall be ______. A. 75, 50 & 5 m B. 500, 150 & 50 m C. 150, 100 & 50 m D. 600, 200 & 100 m Answer: B 10. In a bituminous farm-to-market road, what course is the third layer from the top? A. Aggregate subbase B. Aggregate C. Aggregate base D. Earth Answer: A 11. As an engineer, what thickness of the portland cement concrete pavement will you use in a two-lane farm-to-market road? A. 10 cm B. 20 cm C. 15 cm D. 25 cm Answer: B 28 [email protected] 05 Sep 2022 12. In concrete farm-to-market road construction, what plus or minus in thickness variation will you allow in the portland cement concrete pavement? A. 10 mm B. 20 mm C. 30 mm D. 40 mm Answer: B 13. As a minimum, all culverts and storm drains used in relation with farm-to-market roads should be designed using a storm of two-year return period and duration of ______. A. 6 hours B. 12 hours C. 24 hours D. 18 hours Answer: C 14. Culverts and storm drains have ideal slope of 2-4 %. What is the absolute minimum slope for culverts and storm drains? A. 0.75 % B. 0.5 % C. 1 % D. 1.25 % Answer: B 15. In concrete farm-to-market road design, what class A concrete thickness will you use in triangular concrete-lined ditch? A. 10 cm B. 20 cm C. 15 cm D. 25 cm Answer: C 16. In concrete farm-to-market road design, what wall thickness will you use in rectangular grouted riprap ditch? A. 10 cm B. 15 cm C. 25 cm D. 20 cm Answer: C 17. As a contractor, what project management amount in terms of estimated direct cost percentage will you charge aside from the 10-15 % profit in farm-to-market road projects? A. 7.5% B. 5% C. 10% D. 12% Answer: B 29 [email protected] 05 Sep 2022 C. Irrigation Structures Easy Questions 1. Based on PNS/BAFS/PAES 216:2017, what is the mean roughness coefficient for rigid concrete? A. 0.010 B. 0.012 C. 0.013 D. 0.015 Answer: C 2. The standard diameter of both vertical and horizontal reinforcing bars in open channel construction. A. 8 mm B. 12 mm C. 10 mm D. 16 mm Answer: C 3. In open channel construction, what class of concrete mix should be used? A. Class AA B. Class A C. Class B D. Class C Answer: B 4. The standard spacing between vertical bars in open channel construction. A. 10 cm B. 30 cm C. 20 cm D. 50 cm Answer: C 5. In open channel design, what is the standard concrete wall thickness of lateral trapezoidal open channel? A. 5 cm B. 10 cm C. 15 cm D. 20 cm Answer: C 6. The standard gage number of G.I. tie wire for open channel construction. A. 8 B. 10 C. 16 D. 12 30 [email protected] 05 Sep 2022 Answer: C 7. In class A, B or C concrete, how many cubic meters of sand should be mixed to produce 1 cubic meter of concrete? A. 0.25 B. 0.75 C. 0.50 D. 1.0 Answer: C 8. In open channel construction, how many 40-kg bags of cement are needed per cubic meter of concrete? A. 12 B. 7.5 C. 9 D. 6 Answer: C Moderate Questions 9. In constructing open trapezoidal concrete open channels, how many 900-gm packs of water proofing compound are needed per cubic meter of Class A (1:2:4) concrete mix? A. 9 B. 6 C. 7.5 D. 12 Answer: A Solution: Based on tabular values for Class A concrete mix, No. of packs of water proofing compound = No. of bags of cement = 9 bags 10. In concrete canal 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. 67,500 B. 65,700 C. 113,400 D. 56,700 Answer: C Solution: Bags = Safety factor x Bags cement/cu.m. of concrete x Concrete volume/m x Length in m 31 [email protected] 05 Sep 2022 = 1.05 x 9 bags/cu.m. x 0.6 cu.m/m x 20,000 m = 113,400 bags 11. How many truck loads of sand are needed for 30-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. 1,837 B. 22,050 C. 18,200 D. 18,357 Answer: B 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 30,000 m) = 22,050 truck loads 12. How many truck loads of gravel needed for an 10-km main irrigation canal requiring 4 cubic meters concrete per linear meter? 1 truck load is 2.5 cubic meters. Use 6% safety factor. A. 12,210 B. 13,200 C. 16,960 D. 11,220 Answer: C Solution: Truck loads = Safety factor x Cu.m. gravel/cu.m. concrete x Trucks/cu.m. x Concrete volume = 1.06 x 1 cu.m gravel./cu.m. x 1 truck load/2.5 cu.m. x (4 cu.m/m x 10,000 m) = 16,960 truck loads 13. Determine the cement budget for 36-km irrigation canal if it requires half cubic meter concrete per linear meter and cement costs Php200/bag? Use 5% safety factor. A. Php 1,869,000 B. Php 34,020,000 C. Php 20,900,000 D. Php 18,960,000 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 36,000 m) x Php 200 = Php 34,020,000 32 [email protected] 05 Sep 2022 Difficult Questions 14. The number of 10-mm horizontal reinforcing bars in a 3.2-meter tall trapezoidal canal wall is 2,836 pieces. Following the standard bar spacing 20 cm x 20 cm, how many vertical reinforcing bars are needed? A. 2,836 B. 1,418 C. 5,672 D. 3,800 Answer: A Solution: No need of long computation since the horizontal and vertical bar spacing is the same and the number of horizontal bars is already known, hence No. of vertical bars = No. of horizontal bars = 2,836 bars 15. What is the cement budget for 18-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 2,574,000 B. Php 25,738,000 C. Php 23,825,907 D. Php 25,200,000 Answer: C 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 18,000 m) x (Php 200 + Php 10) = Php 23,825,907 16. The Food and Agriculture Organization of the United Nations (FAO) recommends 1.5 liters/second net irrigation supply per hectare of lowland rice. If the canal is rectangular with base equal to water depth, velocity is 1.2 m/s and area is 50 hectares, what should be the canal base and wetted canal depth excluding freeboard? Assume system efficiency of 16%. A. 6.2 m B. 2.6 m C. 0.62 m D. 0.26 m Answer: C Solution: Q = AV, A = Q/V where A=BD, hence BD = Q/V where B=D, then B2 = Q/V B2 = (1.5 li/s per ha x 1m3/1,000 li x 50 ha / 0.16 system eff.) / (1.2 m/s) B2 = 0.39 m2 B = 0.62 m, equal to wetted canal depth D excluding freeboard 33 [email protected] 05 Sep 2022 16. A gravity dam weighing 73,000 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. 13 tonnes/sq.m. B. 1.2 tonnes/sq.m. C. 1.5 tonnes/sq.m. D. 31 tonnes/sq.m. Answer: C 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 (73,000 tonnes / (1,000 m x 100 m) = 1.46 tonnes/square meter 17. A 1-meter thick trapezoidal section of a concrete dam has resisting moment about the dam toe of 280,000 tonne-meters. The water exerts 4,050 tonnes horizontally at 35 meters above the dam toe. What is the factor of safety against overturning? A. 3.1 B. 1.98 C. 5.2 D. 1.9 Answer: B Solution: Overturning Factor of Safety = Resisting moment/Overturning moment = 280,000 /(4050 x 35) = 1.98 18. A concrete dam with 50,000 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 0.83. What should be the minimum dam weight? Use factor of safety against sliding of 2. A. 57,300,000 tonnes B. 65,783,133 tonnes C. 62,850,000 tonnes D. 62,850 tonnes Answer: B Solution: Sliding Factor 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 50,000 sq.m.) / 0.83 Weight = 65,783,133 tonnes 34 [email protected] 05 Sep 2022 IV. Waste Management (10%) Easy Questions 1. The toxic component of biogas. A. Hydrogen sulfide B. Hydrogen C. Sludge D. Sulfur Answer: A 2. The by-product of biogas production commonly used as soil conditioner after air drying. A. Fertilizer B. Waste C. Sludge D. Slurry Answer: C 3. The amount paid to project owners from CDM fund for carbon emission reduction projects. A. Emission value B. Carbon credit value C. Carbon trading value D. Carbon value Answer: B 4. The acronym of the Inter-Governmental Panel for Climate Change. A. IGPCC B. IPC C. IPCC D. Inter-GPCC Answer: C 5. Best kind of biogas plant for large animal farms having effluents with low solid content. A. Fixed dome B. Covered lagoon C. Floating type D. Balloon Answer: B 6. Plastic sheet for constructing balloon and bed lining in covered lagoon biogas plants. A. High density polyethylene (HDPE) B. Polyvinyl Chloride (PVC) C. Acetate D. UV-stabilized acetate Answer: A 35 [email protected] 05 Sep 2022 7. By how many times is methane destructive to the environment than carbon dioxide? A. 2 times B. 21 times C. 10 times D. 15 times Answer: B 8. Toxic by-product of geothermal power plants. A. Hydrogen sulfide B. Carbon monoxide C. Carbon dioxide D. Sulfuric acid Answer: A 9. When using covered lagoon biodigester, what is approximate methane content in biogas? A. 40% B. 70% C. 50% D. 80% Answer: B 10. What is the minimum methane content of biogas in order to operate biogas-fueled generators? A. 50% B. 85% C. 65% D. 90% Answer: C 11. When using 1:1 water-manure ratio, what is the approximate methane content of biogas? A. 40% B. 60% C. 50% D. 80% Answer: B 12. A device to convert biogas to electricity. A. Converter B. Motor C. Electricity generator D. Biogas generator Answer: D 13. A board constructed across the bottom of the biogas digester to prevent early exit of slurry. A. Baffle board B. Wall C. Divider D. Slurry retainer Answer: A 36 [email protected] 05 Sep 2022 Moderate Questions 14. Covered lagoon biodigester, minihydro and solar energy projects are evaluated for financial feasibility. Only one feasible project can be funded. Each of them requires PHP 20,000,000 investment. The financial internal rates of return are 8%, 9% and 10%, respectively. Annual discount plus inflation rate is 11%. Which project shall be implemented? A. Covered lagoon biodigester B. Minihydro C. None D. Solar Answer: C (since all their IRRs are less than the discount plus inflation rate) 15. In the Clean Development Mechanism (CDM), how much will the project owner of a new covered lagoon biodigester receive annually from CDM fund for the first 10 years if his biodigester produces 8,000 tonnes of methane and 3,000 tonnes of carbon dioxide per year. Assume that the current carbon credit costs US$8 per tonne of carbon equivalent. A. US$ 30,000 B. US$ 100,000 C. US$ 1,368,000 D. US$ 2,200,000 Answer: C 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$ 8 [3,000 + 21(8,000)] = US$ 1,368,000/year 37 [email protected] 05 Sep 2022 Difficult Questions 16. What is the daily biogas consumption in cubic meters of an industrial boiler using 12 units of 50-cm gas burner 8 hours a day? The consumption of each gas burner is 1.3 cu.m./hour. A. 9.6 B. 102 C. 125 D. 80 Answer: C Solution: C = NBT where C= Consumption, N = No. of units, B = biogas consumption of device, T = Time C = (12 units)( 1.3 m3/hr)(8 hrs) = 124.8 m3 17. 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 1,100 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 m 3/kg. A. 97 B. 153 C. 125 D. 193 Answer: B 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 P = (1,100 heads)(2.2 kg/head)(0.063 m3/kg) = 152.46 m3 18. How many heads of breeding cattle are needed as source of manure to generate 80 m 3 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 25- day manure retention period is half of that of chicken dung. A. 192 B. 205 C. 206 D. 139 Answer: C Solution: N = P/(MG) where N = No. of heads, C = biogas production, M = manure production, G = Half of specific gas production of chicken dung for a specific retention period = 1/2 x 0.06 m3/kg or 0.03 m3/kg C = (80 m3)/[(13 kg/head)(0.03 m3/kg)] = 205.13 heads, to avoid gas shortage round up to 206 heads 38 [email protected] 05 Sep 2022 REFERENCES AMTEC, Varied Years. PAES for Agricultural Processing and Structures (Various standards, specific PAES numbers indicated in the questions) AUDELS, ____. Electrical Power Calculations, latest edition Brown, ____. Farm Electrification, latest edition Catchillar, 2008. Fundamentals of Environmental Science DOE and JICA, 2004. Manual for Micro-Hydropower Development Fajardo, ___. Simplified Methods on Building Construction, latest edition FAO, ____. Scheme Irrigation Water Need and Supply. Retrieved August 2022 Philippine Building Code, 1977 Philippine Electrical Code, 2009 Philippine National Standard, 2017. PNS/BAFS/PAES 216:2017 Philippine National Standard, 2019. PNS/BAFS 290:2019 Philippine Agricultural Engineering Journal, Vol. XXX (2) Renewable Energy Journal, Various Issues & Article Authors Tambong, 1992. Biogas Plant Design 39 [email protected] 05 Sep 2022 40 [email protected] 05 Sep 2022 This material was sourced from Bytex Online Through Payhip in London, England, United Kingdom https://payhip.com/bytex Digital Products, Online Courses and Services at Bytex Online: Feasibility Study Preparations Services https://payhip.com/b/MESYt Load plus free software Bytex Feasibility Analyzer, ver. 5.18 Copyrighted by Arthur Tambong, a software for quick preparation of any feasibility study Compliant with IAS & IFRS international standards https://payhip.com/b/dlQ5p Sample Feasibility Studies Compliant with IAS & IFRS International Accounting Standards by Arthur Tambong (varied studies and years) https://payhip.com/b/rYmPg ABE Board Exam Reviewer (Part I) by Arthur Tambong, 2022 https://payhip.com/b/GaT84 ABE Board Exam Reviewer (Part II) by Arthur Tambong, 2022 https://payhip.com/b/DZYzc ABE Board Exam Reviewer (Part III) by Arthur Tambong, 2022 https://payhip.com/b/dRXzS 12 Tips to Pass Board Exams with High Rating by Arthur Tambong, 2022 https://payhip.com/b/pxH3z Introduction to Software-Aided Feasibility Study Preparation by Arthur Tambong, 2022 https://payhip.com/b/Em308 Training Course on Software-Aided Feasibility Study Preparation https://payhip.com/b/Dt5q8 41