2015 Examination for the National Agricultural Technology and Mechanical Systems CDE

Energy: A 200 horsepower eight-cylinder engine is operating at 6865 feet above sea level. What approximate horsepower can be produced by the engine when the engine's power is reduced 2.45 percent for each 1000 feet of elevation above sea level? a. 166.4 horsepower b. 194.2 horsepower c. 136.4 horsepower d. 274.2 horsepower

a. 166.4 horsepower

Energy: A hot waterline is used 6 hours and 45 minutes each day, has three different water leaks, and the amount of water lost at each leak has been measured during a 30 minute time period. The three quantities of water from the leaks are (a) 75 ounces, (b) 68 ounces, (c) 111 ounces. Approximately how many gallons of water will be lost from the waterline during 100 days of operation? 1 gallon= 128 ounces 24 hours= 1 day 60 minutes= 1 hour a. 2,679 gallons b. 13,395 gallons c. 44,648 gallons d. 342,900 gallons

a. 2,679 gallons

Energy: A water pump has a 4.75-inch diameter pulley that must turn at 800 revolutions per minute (rpm). The shaft of a electric motor rotates at 1725 rpm and powers the belt that operates the pump. What is the approximate diameter of the pulley needed on the motor shaft to turn the pump at 800 rpms? Pulley Size Formula: (Diameter of pulley 1 x Speed of Pulley 1 ) = (Diameter of Pulley 2 x Speed of Pulley 2) a. 2.2 inches b. 3.3 inches c. 4.4 inches d. 5.5 inches

a. 2.2 inches

Environmental: A rectangular shaped plastic hopper is used to transport granular pesticide in bulk. This hopper is transported on a trailer with a 500-pound maximum load carrying capacity. The internal dimensions of the hopper are 6.5 feet wide, 8.75 feet long and 4.25 feet deep. What is the maximum weight in pounds per cubic foot(approximate value) that granular pesticide can weigh, completely fill the hopper, and still transport within safe load carrying limits? 1 gallon= 231 cubic inches 1 cubic-foot= 1728 cubic-inches Volume of rectangular prism= Length x Width x Height a. 20.7 lbs / ft3 b. 23.6 lbs / ft3 c. 27.1 lbs / ft3 d. 99.2 lbs / ft3

a. 20.7 lbs / ft3

Electrical: An inefficient electrical motor (identified as motor A) is to be replaces with a new high efficiency motor (identified as motor B). Motor A was operated 8 hours and 30 minutes per day, 322 days each year, and its annual electrical bill averaged $18,983. The purchase price for motor B is $1,318 and the installation charge is $390. Motor B will be operated the same number of hours as motor A and will have an average cost of $5.87 per hour to operate. Approximately how many months must motor B operate to payback the purchase and installation cost of the new motor? 1 year= 12 months 1 day= 24 hours 1 year= 365 days Equipment Payback in months= Total cost for new high efficient equipment / Average saving in energy cost per month a. 7 months b. 84 months c. 125 months d. 294 months

a. 7 months

Electrical: The interior electrical lighting of a farm structure is being replaced with high efficiency lighting. The 24 incandescent, 200- Watt lights will be replaced with 24 LED, 50- Watt lights. If the lights are operated 88 hours per month and electricity cost 10 cents per kilowatt-hour (kWh), what is the approximate reduction in electrical power costs each month? 1000 Watts= 1 kilowatt a. $ 10.56 b. $ 31.68 c. $ 42.40 d. $ 68.82

b. $ 31.68

Machinery: Each cylinder in an eight cylinder tractor engine has a bore (diameter) of 4.85 inches and a piston stroke of 6.25 inches. What is the approximate total displacement of this engine in liters? Area of a cylinder bore= (pi) x (radius)^2 pi= 3.14 radius= (diameter/ 2) Volumetric displacement of a single cylinder= (length of piston stroke) x (the areas of the cylinder bore) 1 liter= 61 cubic inches 1 cubic inch= 0.0164 liter a. 1.9 liters b. 15.1 liters c. 60.5 liters d. 900.5 liters

b. 15.1 liters

Machinery: A tractor's power takeoff produces 325 horsepower and turns at 1000 revolutions per minute. Approximately how much torque, in foot-pounds, can this PTO produce? Torque in foot-pounds = PTO Horsepower x 5252/ Revolutions/Minute a. 1652.4 foot-pounds b. 1706.9 foot-pounds c. 1841.2 foot-pounds d. 1927.5 foot-pounds

b. 1706.9 foot-pounds

Energy: An available electronic thermometer is calibrated in degrees Celsius ( C ). A pesticide label specifies that the maximum allowable temperature for spray application is 75 degrees Fahrenheit ( F ). What is the approximate temperature equivalent in degrees Celsius? F= (9/5 C) + 32 C= 5/9 (F-32) Water freezes at 32 F Water boils at 212 F a. 9.7 C b. 23.9 C c. 41.7 C d. 167.0 C

b. 23.9 C

Energy: An electrical water heaters uses 800 kilowatt-hours (kWh) of power each day. If electric power cost 11.5 cents per kWh, approximately how much energy (in the rms) does this water heater use during 22 days of operation? British Thermal Unit= BTU 1 kWh= 3412.3 BTUs of energy 1 therm of energy = 100,000 BTUs of energy a. 306.0 therms b. 660.6 therms c. 933.6 therms d. 7507.0 therms

b. 660.6 therms

Structural: A pesticide spray tank has a cylindrical shape that is 7 feet 9 inches long with a radius of 2 feet. What is the approximate total storage capacity of tank in gallons? 1 gallon= 231 cubic inches 1 foot=12 inches pi= 3.14 Diameter= 2 x (radius) Volume of a Cylinder= (pi) x (radius)^2 x (length) 1728 cubic inches= 1 cubic foot a. 97 gallons b. 728 gallons c. 972 gallons d. 1,438 gallons

b. 728 gallons

Electrical: A pesticide boom sprayer with eight spray nozzles is mounted on the back of an ATV (4-wheeler) and the pump motor is powered by the 12 volt battery of the vehicle. The spray pump's range of operation for spraying application is 20 to 45 pounds per square inch (PSI), but there is a 20% loss in pressure due to the spray system's components. If each nozzle must deliver a range of 0.02 to 0.04 gallons per minute (GPM), which of the following motors is most economical to purchase and also has the appropriate capacity and specifications for this boom sprayer. VDC= direct current voltage VAC= alternating current voltage a. Motor A, rated at 12 VDC, cost $219, and delivers up to 5 GPM at 100 PSI b. Motor B, rated at 12 VDC, cost $149, and delivers up to 2 GPM at 65 PSI c. Motor C, rated at 12 VDC, cost $119, and delivers up to 3.2 GPM at 45 PSI d. Motor D, rated at 12 VAC, cost $93, and delivers up to 2.1 GPM at 65 PSI

b. Motor B, rated at 12 VDC, cost $149, and delivers up to 2 GPM at 65 PSI

Machinery: Approximately how many acres are in a rectangular field measuring 1109 meters by 928 yards? 1 acre= 43,560 sq ft 1 hectare= 2.47 acres 1 acre=0.4045 Hectares Area of a rectangles= Length x Width 1 yard= 3 feet 1 foot= 0.3048 meter a. 2.4 acres b. 23.6 acres c. 232.5 acres d. 2325.4 acres

c. 232.5 acres

Electrical: A water supply station used to refill pesticide tanks has a 4 horsepower electrical pump that operates at 120 volts. If the motor is 85 percent efficient and has a 0.9 power factor, what is the approximate amperage of the motor? Horsepower= voltage x amperage x power factor x efficiency / 746 1 horsepower= 746 Watts a. 8.1 amps b. 27.6 amps c. 32.5 amps d. 253.6 amps

c. 32.5 amps

Environmental: A concrete slab will be installed to prevent contamination of the ground at a mixing and cleaning site for pesticide equipment. The inside dimensions of the slab's form boards are 24 feet wide by 14 feet long and the concrete forms provide an approximate depth of 5 inches. Order an additional 10 percent concrete to allow for any inconsistencies in the ground surface and note that pre-mixed concrete is sold/ delivered in quarter-yard quantities ( such as: 3yd3, 6.25 yd3, 10.75 yd3, 15.5 yd3). Approximately how many cubic yards (yd^3) of pre-mixed concrete should be ordered? 1 cubic yard= 27 cubic feet 1 cubic foot= 1728 cubic inches 1 foot= 12 inches Volume of a rectangular prism= Length x Width x Height a. 3.50 yd3 b. 5.25 yd3 c. 5.75 yd3 d. 68.50 yd3

c. 5.75 yd3

Structural: There is concern that the numerical values marked on a 500 gallon pesticide spray tank are inaccurate and water weight will be used to determine and confirm tank volume values. The weight of the empty tank is 92 pounds. What should the approximate combined weight (pounds, lbs) be for the tank and water if the test weights are done at 100 gallons, 250 gallons and 500 gallons? 1 gallon of water = 8.34 pounds a. 834 lbs for 100 gallons; 2085 lbs for 250 gallons; 4170 lbs for 500 gallons b. 926 lbs for 100 gallons; 2177 lbs for 250 gallons; 4170 for 500 gallons c. 926 lbs for 100 gallons; 2177 lbs for 250 gallons; 4262 lbs for 500 gallons d. 1018 lbs for 100 gallons; 2269 lbs for 250 gallons; 4262 lbs for 500 gallons

c. 926 lbs for 100 gallons; 2177 lbs for 250 gallons; 4262 lbs for 500 gallons

Environmental: IF the delivery rate ( gallons per minute) of a worn or damaged spray tip on a boom sprayer exceeds 10% (higher or lower) of the average for all of the nozzles, then that nozzle's spray tip should be replaced. The following delivery rates (in ounces; oz) were measured during 20-second time period. Which if any nozzle spray tips should be replaced? Tip 1= 13.5 oz; Tip 2= 12 oz; Tip 3= 10.5 oz; Tip 4= 12.5 oz; Tip 5= 13 oz; Tip 6= 14 oz a. Replace tips 1 and 4 b. Replace tips 2 and 5 c. Replace tips 3 and 6 d. All tips within 10 %

c. Replace tips 3 and 6

Electrical: Three incandescent light bulbs ( 100 Watts, 200 Watts, 300 Watts) are operating in a 120 volt circuit. If each bulb operates at its rated wattage, which of the following statements is correct in regard to the operation of the bulbs? Wattage= Voltage x Amperage Voltage= Amperage x Resistance a. All three bulbs operate at the same amperage. b. All three bulbs have the same electrical resistance c. The 100- watt light bulb has more electrical resistance (ohms) than the 200 or 300- watt light bulbs. d. The 100-watt light bulb has less electrical resistance (ohms) than the 200 or 300- Watt light bulbs.

c. The 100- watt light bulb has more electrical resistance (ohms) than the 200 or 300- watt light bulbs.

Machinery: A tractor mounted pesticide sprayer has 36 Teejet nozzles uniformly spaced along a spray boom. The applicator prefers to travel at 5 miles per hours (MPH) and wants to apply the pesticide and water mixture at a rate of 20 gallons per acre (GPA) to provide good coverage of the target site. Which of the following combinations of nozzle tip sizes and nozzle spacing will provide the target site. Which of the following combinations of the nozzle tip sizes and nozzle spacing will provide the approximate coverage required given the above parameters? This spray equipment is operated at 40 lbs per sq inch (PSI) as recommended by Teejet. Gallons Per minute / Nozzle = GPA x MPH x Nozzle Spacing in inches / 5940 a. XR Teejet 8001 VS with 20 inch nozzle spacing b. XR Teejet 11002 VS with 22 inch nozzle spacing c. XR Teejet 8004 VS with 24 inch nozzle spacing d. XR Teejet 11008 VS with 26 inch nozzle spacing

c. XR Teejet 8004 VS with 24 inch nozzle spacing

Structural: Steel angle iron is sold for $2.11 per linear foot, steel rod is sold for $1.91 per linear foot, and steel pipe is sold for $3.19 per linear foot. If 28.5 feet of angle iron, 23 feet of rod, and 15.5 feet of pipe are purchased, what is the approximate total price for the metal before taxes? a. $ 60.15 b. $ 93.36 c. $ 109.58 d. $ 153.51

d. $ 153.51

Environmental: A large volume of water contaminated with liquid pesticide (water and liquid pesticide) was collected from a runoff of a mixing and loading concrete pad. Initially the liquid is 6% pesticide and 94% water. Over the summer much of the water evaporates and only 42% of the water remains. All of the pesticides still remains. What is the approximate percentage pf pesticide in the remaining liquid? a. 9.9% pesticide b. 11.4% pesticide c. 12.1% pesticide d. 13.2% pesticide

d. 13.2% pesticide

Structural: A round concrete column is fabricated using 2.25 cubic yards of concrete. If the concrete column is 2 feet 4 inches in diameter, what is the approximate height of the column? 1 cubic yard = 27 cubic feet 1 cubic foot= 1728 cubic inches 1 foot= 12 inches Volume of a cylinder= pi x (cylinder radius)^2 x cylinder height pi = 3.14 diameter = (r x radius) a. 5.4 feet b. 9.7 feet c. 11.9 feet d. 14.2 feet

d. 14.2 feet

Environmental: What is the approximate annual power consumption (kilowatt-hours, kWh) of a 240 volt electrical installation with 36 lights, each light using 0.95 amps and operating an average of 9 hours and 30 minutes each day, and 22.5 days per month? 1 year=12 months Kilowatt=100 Watts Watts= Volts x Amps Volts=Amps x Resistance in Ohms Kilowatt-hours=Kilowatts x hours a. 1,717.5 kWh b. 2,169.3 kWh c. 20,610.3 kWh d. 21,054.5 kWh

d. 21,054.5 kWh

Structural: Which of the following quantities of lumber has the greatest number of board-feet? 1 board foot= 144 cubic inches 1 square foot= 144 square inches a. 52 boards measuring 1 inches by 6 inches by 14 feet b. 27 boards measuring 2 inch by 8 inches by 10 feet c. 45 boards measuring 2 inches by 6 inches by 8 feet d. 46 boards measuring 1 inch by 8 inches by 12 feet

d. 46 boards measuring 1 inch by 8 inches by 12 feet

Machinery: A tractor powered herbicide boom sprayer with 24 spray nozzles, spaced 20 inches apart, is setup and calibrated to spray weeds in forage crops. The sprayer delivers a herbicide and water mixture at a uniform rate of 17.5 gallons per acre, travels at 4.75 miles per hour (MPH), and operates at a spray pressure of 30 pounds per square inch (PSI). An unusually high weed infestation requires an increase in the application of the herbicide mixture to 20 gallons per acre (GPA). Which of the following changes to one of the sprayer's operating parameters will most closely achieve 20 GPA? Gallons per minute / Nozzle = GPA x MPH x Nozzle spacing in inches / 5940 Pressure Formula: New PSI = (original PSI) x (New GPM / Original GPM) ^2 a. Decrease speed from 4.75 MPH to 4.5 MPH b. Decrease speed from 4.75 MPH to 4.25 MPH c. Increase pressure from 30 PSI to 34 PSI d. Increase pressure from 30 PSI to 39 PSI

d. Increase pressure from 30 PSI to 39 PSI