ABE Reviewer 2024 Volume 1

Agricultural and BIosystems Power Engineering

In a 4-stroke diesel engine, which stroke produces power to do mechanical work?

A. Induction stroke

B. Compression stroke

C. power stroke

D. Exhaust stroke

D. Exhaust stroke

Based on diesel fuel thermodynamics, high temperature during fuel explosion in an engine results to

a. high combustion chamber pressure

b. faster rotation of the crankshaft

c. exhaust valve opening

d. inlet valve closure

a. high combustion chamber pressure

due to small engine space in mobile fisheries equipment, they are best manufactured using a

a. 1-stroke

b. 2-stroke

c. 4-stroke

d. 6-stroke

c. 4-stroke

in an internal combustion engine, the ___ converts linear motion of the piston to rotational motion

a. crankshaft

b. cam

c. connecting rod

d. crank

a. crankshaft

in a diesel engine, at what stroke is fuel injected into the cylinder?

a. induction stroke

b. compression stroke

c. power stroke

d. exhaust stroke

b. compression stroke

in a diesel engine, the temperature of the compressed air reaches about ___ degrees Fahrenheit.

a. 130

b. 1300

c. 13000

d. 3100

b. 1300

in a gasoline engine, which of the following parts is absent?

a. spark plug

b. oil ring

c. compression ring

d. fuel injector

d. fuel injector

in a diesel engine, what causes the fuel to explode?

a. high compression

b. high temperature

c. friction

d. spark

b. high temperature

inside the diesel cycle engine, the high temperature needed for fuel explosion is attained at

a. fast piston stroke

b. ring friction with the cylinder

c. high fuel pressure

d. high air pressure

d. high air pressure

the piston of a 4-stroke engine typically has __ or more comrpression rings and at least 1 oil scraper ring.

a. 1

b. 2

c. 3

d. 4

b. 2

in the thermodynamics of fuel inside an internal combustion engine, the constant volume cycle is also known as

a. otto cycle

b. diesel cycle

c. carbon cycle

d. motor cycle

a. otto cycle

in today’s otto cycle engine, the fuel is

a. gun powder

b. gasoline

c. diesel

d. pure bioethanol

b. gasoline

the fuel for diesel cycle engine is

a. gun powder

b. gasoline

c. diesel

d. bioethanol

c. diesel

four-wheel tractors have normally __ engine

a. 1-stroke

b. 2-stroke

c. 4-stroke

d. 6-stroke

c. 4-stroke

due to high power requirement, four-wheel tractors are normally manufactured using __ engines.

a. diesel cycle

b. otto cycle

c. carbon cycle

d. water cycle

a. diesel cycle

a high-power diesel cycle engine used in tractors can be fueled by diesel blended with

a. bioethanol

b. biodiesel

c. methanol

d. gasoline

b. biodiesel

a high power otto cycle engine used in aquaculture engineering can be fueled by gasoline blended with

a. bioethanol

b. biodiesel

c. kerosene

d. diesel

a. bioethanol

in otto cycle engine, fuel explosion occurs at

a. constant volume

b. constant pressure

c. constant temperature

d. constant power

a. constant volume

in diesel cycle engine, fuel explosion occurs at

a. constant volume

b. constant pressure

c. constant temperature

d. constant power

b. constant pressure

the __ controls the opening and closing of intake and exhaust valves of internal combustion engines.

a. connecting rod

b. piston ring

c. crankshaft

d. camshaft

d. camshaft

during power stroke in an engine, the __ trnasmits mechanical power to the crank.

a. connecting rod

b. piston ring

c. crankshaft

d. camshaft

a. connecting rod

in a gasoline engine, the ___ initiates the fuel explosion.

a. fuel injector

b. spark plug

c. igniter

d. friction

b. spark plug

in a 2-stroke gasoline engine, the crank makes __ revolution(s) while the piston makes 2 strokes to complete the cycle of events.

a. 1

b. 2

c. 3

d. 4

a. 1

when the engine is in operation, the pressure inside a fuel injector must be __ than the pressure inside the diesel engine combustion chamber.

a. higher

b. twice lower

c. thrice lower

d. 0.5 times higher

a. higher

during combustion inside the engine __ is pushed downward.

a. crank

b. crankshaft

c. piston

d. exhaust value

c. piston

in engine maintenance, when changing the engine oil, the __ must also be changed.

a. air filter

b. oil filter

c. fuel strainer

d. oil strainer

b. oil filter

changine the engine oil is regular every certain number of hours used or certain number of kilometers traveled (For vehicles) recommended by the manufacturer but it is mandatory when the oil color is

a. brown

b. yellow

c. black

d. colorless

c. black

in engine repair, what is the first step?

a. inspecting and disassembling the engine block

b. removing the engine

c. disassembling the cylinder head

d. reassembling the engine block

b. removing the engine

a long metal for determining the correctness of oil level duriing regular inspection of big engines.

a. oil sticl

b. oil gauge

c. oil dipstick

d. oil meter

c. oil dipstick

a valve spring compressor looks like a

a. hack saw

b. vise grip

c. pipe wrench

d. adjustable wrench

c. pipe wrench

when installing new piston rings, the tiny gaps at the end of rings are turned about ___ degrees apart around the piston.

a. 30

b. 60

c. 90

d. 180

d. 180

a mechanical device for lifting up and lowering down heavy engines.

a. hoist

b. chain

c. jack

d. lever

a. hoist

appropriate equipment or tool for installing the engine cylinder sleeves into the engine block.

a. hydraulic press

b. jack

c. hammer

d. jack hammer

a. hydraulic press

in installing the crankshaft into the engine block, bolt tightening is gradual and simultaneous for all bolts until the torque is about __ foot-pounds.

a. 60

b. 120

c. 180

d. 240

c. 180

to keep a tractor engine running seamlesslyy and efficiently, its maintenance should be

a. done when it starts to knock

b. regular as recommended by the manufacturer

c. once a year

d. monthly

b. regular as recommended by the manufacturer

in dismantling the engine cylinder head, what tool will you use in compressing the valve springs to remove the valve keepers?

a. screwdriver

b. mechanical pliers

c. valve spring compressor

d. valve spring remover

c. valve spring compressor

using the correct tractor engine oil is essential for keeping your tractor’s engine running smoothly and the oil should meet the oil specifications of the

a. PNS

b. oil dealer

c. tractor supplier

d. tractor manufacturer

d. tractor manufacturer

a 4-stroke diesel engine of a rice processing center overheats frequently. water drops below the engine. what is the most possible cause of overheating?

a. malfunctioning radiator fan

b. low coolant level

c. broken water pump

d. low oil level

c. broken water pump

an otto cycle engine us used in a locally assembled transport vehicle for a sugarcane plantation. it was frequently observed by the operator that the engine stops when it climbs up a slightly slopping farm-to-market road. analyze. what repair job will you do to solve the problem?

a. replace the engine with diesel engine of the same space requirement but of higher rated power

b. reduce carriage volume to reduce load

c. tighten the timing belt to minimize slippage

d. rebore the engine cylinders to increase power

a. replace the engine with diesel engine of the same space requirement but of higher rated power

a diesel engine starts normally but produces a knowcking sound few minutes after starting. the engine has not been opened for relatively longer time. no mechanic is available is available in the area to open the engine. analyze. what is the possible casue and what is your first move to alleviate the problem?

a. defective spark plugs, clean spark plugs

b. malfunctioning fuel injector, replace injector

c. broken compression ring, weld compression ring

d. high carbon deposit at the combustion chamber, use an additive to wear out carbon deposit

d. high carbon deposit at the combustion chamber, use an additive to wear out carbon deposit

a transport vehicle smells gasoline in the hood area when running. what part should you inspect immediately and what you should look for?

a. fuel tank, for crack

b. accelerator pedal, for adjustment

c. fuel hose, for leakage

d. air conditioner’s evaporator, for crack or leakage

c. fuel hose, for leakage

a rice transport vehivle uses gasoline engine. the engine does not start when the key is turned on and no starting sound can be heard. what part that is connected to the engine will you inspect first?

a. spark plug

b. battery

c. fuel line

d. fuel injector

b. battery

a fishing company is planning to buy a 105-hp diesel engine for the rehabilitation of its fishing boat. the company consults you as AB engineer to analyze and recommend immediately as to what unit to purchase: a 10-year old PHP100,000 second hand functional engine or a brand new PHP500,000 engine of the same brand? what wil be your recommendation?

a. buy the 10-year old engine to reduce engine cost

b. buy the new engine to reduce maintenance cost

c. buy any of the two engines

d. defer recommendation for an in-depth analysis

b. buy the new engine to reduce maintenance cost

what is the ultimate source of energy?

a. fossil fuel

b. geothermal

c. solar radiation

d. sun

d. sun

a tipping bucket rain gage equipped with transmitter was designed to send rainfall data to a distant agrometeorological station. it is to be installed beside a creek in a remote area. it consumes 11.1 milliwatts. what is the appropriate source of power?

a. picohydro

b. microhydro

c. small hydro

d. minihydro

a. picohydro

A picohydro generator is to be used as power source for an analog pressure transmitter sending real-time data on water depth at dam outlet. The pressure transmitter has a voltage of 15 Volts DC and amperage of 20 milliamperes. What minimum power output and voltage of picohydro generator should you request for purchasing?

A. 36 watts, 15 Vdc

B. 365 milliwatts, 15 Vdc

C. 280 milliwatts, 12 Vdc

D. 250 milliwatts, 12 Vdc

B. 365 milliwatts, 15 Vdc

estimate the dependable power output from a windpump having a rotor diameter of 8 meters, average blade twist angle of 45 degrees, and tip speed ratio of 1:1 if the daytime prevailing windspeed in the location is 3 meters/second.

a. 135 watts

b. 6.1 kW

c. 163 watts

d. 3.1 watts

a. 135 watts

the pumping power requirement of a new large livestock farm adjacent to a river is 102 kW. you are the project consultant. what power source will you recommend?

a. minihydro

b. microhydro

c. windpump

d. solar pump

d. solar pump

estimate the dependable power output and system efficiency of a microhydro having a gross head of 60 meters, minimum water discharge of 150 liters/second, and penstock water velocity of 12 m/s.

a. 52 kW, 60% efficiency

b. 635 kw, 60% efficiency

c. 75 kw, 85% efficiency

d. 6.2 kw, 85% efficiency

a. 52 kW, 60% efficiency

determine the daily energy output of a 24-volt DC solar pump during a sunny day in Luzon with latitude of 16 degrees north if its overall power output is 750 watt-peak and the daily sensible sunlight in the location is 5 hours.

a. 30 kwh

b. 6.3 kwh

c. 3.75 kwh

d. 90 kwh

c. 3.75 kwh

a solar water heater installed in mindanao at latitude of 8 degrees north is used for pre-heating water prior to entry into industrial-size boilers. the heater has a collectopm area of 3.6 meters x 5 meters, and efficiency of 9%. Estimate its power output during a sunny noon if you are tasked to carry out the installation and north-south orientation.

a. 16 kw, 8 degrees facing north

b. 6.1 kw, 10 degrees facing south

c. 1.6 kw, 8 degrees facing north

d. 1.6 kw, 10 degrees facing south

d. 1.6 kw, 10 degrees facing south

water needs to be elevated into a farm house 30 meters above an existing 10-meter high waterfalls. what renewable energy system will you install for pumping water?

a. windpump

b. ram pump

c. submersible pump

d. solar pump

b. ram pump

a cassava flour processing plant requiring 3-MW power is located in a remote area where electricity grid is 50 km away but has a waterfall inside its perimeter fence with dependable 6 cubic meters per second discharge and 100 meters height. in your calculation, what is the appropriate power source?

a. minihydro

b. small hydro

c. microhydro

d. picohydro

a. minihydro

a 24-volt DC generator is to be acquired to support DC electrical loads including motors. the computed maximum amperage at peak load is 10 amperes. surge current is assumed 25% higher than the computed peak load amperage. load safety factor of 20% is to be used. if you are carry out the acquisition, what minimum wattage of the generator should be selected?

a. 300

b. 306

c. 360

d. 630

c. 360

a 360-watt power from a 12-volt DC generator is to be used for AC farm machine by using an inverter. whatis the power output from the inverter if inversion efficiency is 85%?

a. 300

b. 306

c. 360

d. 630

b. 306

an AC generator is rated at an apparent power of 100 KVA with a power factor of 0.8. what is the real power of the generator in kW?

a. 74.6

b. 80

c. 107

d. 109

b. 80

an AC generator is rated at an apparent power of 100 KVA with a power factor of 0.8. what is the real power of the generator in hp?

a. 80

b. 74.6

c. 107

d. 109

c. 107

an AC generator is rated at a real power of 90 kW with an indicated power factor of 0.82, what is the apparent power of the generator?

a. 80

b. 74.6

c. 107

d. 109

d. 109

the generally accepted industry standard for power factor of generators.

a. 80%

b. 75%

c. 90%

d. 100%

a. 80%

in DC generators and DC circuits, the power factor is always

a. 80%

b. 75%

c. 90%

d. 100%

d. 100%

the property of the engine oil that determines the lubricant’s film strength and efficiency in preventing friction between moving parts.

a. viscosity

b. alkalinity

c. detergency

d. load carrying detergency

a. viscosity

the minimum flash point of oil used in engines necessary to prevent fire

a. 220 degrees Celsius

b. higher than 220 degrees Celsius

c. lower than 220 degrees Celsius

d. 220 degrees Fahrenheit

b. higher than 220 degrees Celsius

classify the tandem of properties of liquid fuels below. which tandem is not applicable in the Philippines when delaing with oepration, repair, and maintenance of internat combustion engines?

a. viscosity and alkalinity

b. viscosity and detergency

c. alkalinity and detergency

d. cloud point and pour point

d. cloud point and pour point

if you are to carry out engine oiling of newly acquired 10 units diesel four-wheel tractors which are still within the break-in period, which engine oil shall you use?

a. high viscosity petrol enginel oil

b. low viscosity petrol engine oil

c. low viscosity diesel engine oil

d. high viscosity diesel engine oil

c. low viscosity diesel engine oil

compare the following liquid fuels in terms of specific heat or the amount of energy required to increase the temperature of unit mass of fuel by 1 degrees Celsius. which one has the lowest specific heat?

a. diesel

b. gasoline

c. kerosene

d. ethanol

a. diesel

the specific heat of gasoline is 0.53 kcal/(kg C). if the current temperature of a 1 kg gasoline is 100 degrees Celsius, find the amount of energy needed to further iincrease it to 110 degrees Celsius.

a. 4.8 kcal

b. 5.3 kcal

c. 5.2 kcal

d. 20.5 kcal

b. 5.3 kcal

the specific heat of gasoline is 0.48 kcal/(kg C). if the current temperature of a 1 kg diesel is 200 degrees Celsius, find the amount of energy needed to further iincrease it to 210 degrees Celsius.

a. 4.8 kcal

b. 5.3 kcal

c. 5.2 kcal

d. 20.5 kcal

a. 4.8 kcal

based on the specific gravity of liquid fuels, which of the following fuels is lighter than water?

a. diesel

b. kerosene

c. gasoline

d. diesel, kerosene, and gasoline

d. diesel, kerosene, and gasoline

based on the density of liquid fuels, which of the following fuels can attain the highest tonnage per thousand liters of storage volume?

a. crude oil

b. gasoline

c. diesel

d. biodiesel

a. crude oil

based on the density of liquid fuels, which of the following fuels require the biggest storage volume per tonne of fuel?

a. crude oil

b. gasoline

c. diesel

d. biodiesel

b. gasoline