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1048 Exam Bank
Question block created by wizard
1. A four stroke (4 cycle) diesel exhibits which of the following characteristics?
¡(a)2 injections every revolution.
¡(b)1 injection every 4 revolutions.
¤(c)1 injection every 2 revolutions.
¡(d)4 injections every revolution.
If choice c is selected set score to 1.
2. Compression ratio is the ratio of the
¡(a)clearance volume to the swept volume
¡(b)firing pressure to compression pressure.
¡(c)cylinder pressure at BDC to cylinder pressure at TDC.
¤(d)clearance volume plus the swept volume divided by the clearance volume.
If choice d is selected set score to 1.
3. The most notable difference between a diesel and gasoline engine is the
¡(a)gasoline engine is heavier built.
¤(b)method of fuel ignition.
¡(c)method of combustion air delivery.
¡(d)diesel has a lower compression ratio.
If choice b is selected set score to 1.
4. What creates the heat to ignite the fuel in a diesel engine?
¡(a)Spark plugs.
¡(b)Glow plugs.
¡(c)Preheaters in the air inlet.
¤(d)Heat of compression.
If choice d is selected set score to 1.
5. What does a two stroke diesel require that a four stroke diesel may or may not have?
¡(a)Jerk Pumps.
¡(b)Intake and exhaust valves.
¡(c)Fuel injection system
¤(d)Scavaging air pump.
If choice d is selected set score to 1.
6. Which of the following differences between a gasoline and a diesel engine are true?
¤(a)Spark plugs are not needed to ignite fuel in a diesel.
¡(b)Diesel always have a turbocharger.
¡(c)Gasoline engines compression ratios are higher.
¡(d)The injection ports are larger on a diesel carburetor.
If choice a is selected set score to 1.
7. Which of the following statements best describes a 4-cycle (4 stroke) engine?
¡(a)Four power strokes for every four revolutions of the engine.
¡(b)Two power strokes for every revolution of the engine.
¤(c)One power stroke for every two revolutions of the engine.
¡(d)One power stroke for every revolution of the engine
If choice c is selected set score to 1.
8. A dribbling or leaking fuel injector will
¡(a)Allow exhaust backflow in the injector.
¤(b)Lead to carbon buildup in the cylinder.
¡(c)Increase the diesel engine power output.
¡(d)Cause the diesel engine to overspeed.
If choice b is selected set score to 1.
9. Fuel injector "pop" pressure would be closest to
¡(a)Turbocharger discharge pressure.
¡(b)Compression pressure.
¡(c)Intake manifold pressure.
¤(d)Firing Pressure.
If choice d is selected set score to 1.
10. When the diesel fuel is forced through the injector tip it is
¡(a)Condensed.
¤(b)Atomized.
¡(c)Carbonized.
¡(d)Liquified.
If choice b is selected set score to 1.
11. Which of the following best describes the requirements for a diesel fuel injection system?
¡(a)Fuel injection pressure is less than compression pressure.
¡(b)Fuel must be injected in the largest droplets possible.
¤(c)Fuel injection must be higher than compression pressure.
¡(d)Fuel injection amount is independent of engine load.
If choice c is selected set score to 1.
12. Which of the following is NOT true about proper fuel injection?
¡(a)Injection pressure must be higher than the cylinder pressure.
¡(b)Fuel must be atomized to increase the surface area.
¤(c)Injection must start before the bottom of the stroke.
¡(d)Quantity of fuel injected must change with load changes.
If choice c is selected set score to 1.
13. Why is it necessary to atomize the fuel in the combustion chamber?
¡(a)To ensure no solid particles remain in the fuel
¤(b)To increase the surface area for faster vaporization
¡(c)To break the molecular bonds prior to ignition
¡(d)To ensure that every atom is separated from each other
If choice b is selected set score to 1.
14. A diesel classified as "double acting" means:
¡(a)The engine can be used for marine or land based applications.
¤(b)Combustion takes place on both sides of the piston.
¡(c)The engine's rotation is reversible.
¡(d)Power can be taken off either end of the crankshaft.
If choice b is selected set score to 1.
15. A diesel classified as "single acting" means
¤(a)Combustion takes place only on one side of the piston.
¡(b)It operates in one direction only.
¡(c)Combustion takes place on both sides of the piston.
¡(d)The engine has only one purpose.
If choice a is selected set score to 1.
16. Diesels are classified by
¡(a)Cam shaft arrangement and number of cycles.
¡(b)Cam shaft arrangement and type of fuel used.
¤(c)Cylinder arrangement and number of cycles.
¡(d)Cylinder arrangement and type of fuel used.
If choice c is selected set score to 1.
17. If a diesel is an "Opposed Piston" type,
¤(a)There are two pistons on different crankshafts in each cylinder.
¡(b)The cylinder head is hemispherical in design.
¡(c)There are two pistons on a common crankshaft in cylinders 180 degrees apart.
¡(d)The cylinders are located next to each other at an angle.
If choice a is selected set score to 1.
18. A turbocharger
¡(a)Prevents positive pressure in the crankcase which could cause a crankcase explosion.
¡(b)Requires no aftercooling since the air is being exhausted straight to the atmosphere.
¤(c)Uses the energy in the exhaust gases to run a compressor, using the energy that would otherwise be wasted.
¡(d)Is used to reduce the exhaust backpressure, making the engine exhaust more efficient.
If choice c is selected set score to 1.
19. High exhaust back pressure will cause:
¡(a)A power increase and a decrease in fuel consumption.
¤(b)A power loss and an increase in fuel consumption.
¡(c)A power increase and an increase in fuel consumption.
¡(d)A power loss and a decrease in fuel consumption.
If choice b is selected set score to 1.
20. In addition to providing clean air for combustion the air intake system provides cooling for the:
¡(a)Turbocharger vanes.
¡(b)Fuel Injectors.
¡(c)Intercooler on turbocharged diesels.
¤(d)Piston and combustion chamber.
If choice d is selected set score to 1.
21. The types of air cleaners are
¡(a)Cartridge, oil bath, and dry.
¡(b)Oil bath, wet, and web.
¤(c)Dry, oil bath, and wet.
¡(d)Dry, cartridge, and web.
If choice c is selected set score to 1.
22. What is the purpose of the muffler on the diesel exhaust system?
¤(a)Dampen sound to minimize noise from the engine exhaust
¡(b)Raise backpressure in the exhaust system
¡(c)Increase turbulance in the exhaust system to pervent particulate buildup
¡(d)Pump the exhaust gases out of the exhaust system
If choice a is selected set score to 1.
23. Which of the following has the greatest effect on the turbocharger speed and output?
¡(a)Air intake temperature.
¡(b)Engine condition.
¡(c)Turbocharger governor.
¤(d)Engine load.
If choice d is selected set score to 1.
24. Wet, Dry, and Water Jacketed are types of
¡(a)Air cleaners.
¡(b)Oil filters.
¡(c)Fuel coolers.
¤(d)Cylinder liners.
If choice d is selected set score to 1.
25. Which of the following is NOT considered a function of the Lubricating Oil System?
¡(a)Keeps engine parts lubricated to minimize friction.
¤(b)Provides hydraulic action to lift piston rings.
¡(c)Provide some cooling to the engine components.
¡(d)Help prevent rust and corrosion in the engine.
If choice b is selected set score to 1.
26. Which of the following is true of the diesel lube oil system?
¤(a)It reduces friction, dissipates some engine heat, is splash lubricated and/or pressurized.
¡(b)The quality of oil is not critical since temperatures are not as high as in gasoline engines.
¡(c)Lube oil filters are always on a bypass line so they can be cut out if necessary.
¡(d)The lube oil is designed to cool the diesel, so that smaller radiators can be used.
If choice a is selected set score to 1.
27. Which of the following types of cooling systems would be the most preferable to minimize corrosion in the cylinder water jackets?
¡(a)Open cooling system.
¡(b)Evaporative cooling system.
¤(c)Closed cooling system.
¡(d)Borated cooling system.
If choice c is selected set score to 1.
28. The Ash Content of diesel fuel is
¡(a)Ash left in the fuel from filtering.
¡(b)Matter left after distilling diesel fuel.
¤(c)Abrasive material left after combustion.
¡(d)Material added to increase viscosity.
If choice c is selected set score to 1.
29. The Flash Point of diesel fuel is
¡(a)The ability of the fuel to change to vapor.
¡(b)How much power the fuel will provide when burned.
¡(c)The temperature at which the vapor will ignite without being in contact with a flame.
¤(d)The temperature at which the vapor given off will ignite when in contact with a flame.
If choice d is selected set score to 1.
30. The heat value of diesel fuel refers to
¤(a)How much power fuel will provide when burned.
¡(b)Abrasive material left after burning the fuel.
¡(c)Matter left after combustion.
¡(d)Ability to change into a vapor.
If choice a is selected set score to 1.
31. The Sulphur Content of diesel fuel is a concern because
¡(a)It causes too much power per cylinder.
¤(b)It causes varnish deposits.
¡(c)It leaves abrasive material after combustion.
¡(d)It's toxic to the diesel operator.
If choice b is selected set score to 1.
32. What is the purpose of the Day Tank?
¡(a)It is a central drain collection tank for unused fuel oil prior to draining back into the storage tanks.
¡(b)It prefilters the fuel oil before it goes to the diesel.
¡(c)Heats up the incoming fuel oil to assist in "dieseling".
¤(d)Provides a volume of fuel prior to delivery to the engine and helps measure fuel consumption.
If choice d is selected set score to 1.
33. Which of the following best describes why diesel fuel storage tanks have a sump located in the tank?
¡(a)Provides higher net positive suction head to the fuel transfer pump.
¡(b)It is the area where all the fuel is pulled out so floating impurities are not pulled up.
¤(c)Provides an area for collection and removal of water and sludge.
¡(d)It allows for better venting of the storage tank.
If choice c is selected set score to 1.
34. The unit injectors
¡(a)Replace the old style rotary injectors.
¡(b)Combine the function of the injector and glow plug.
¤(c)Combine the function of jerk pump and injector.
¡(d)Cost more then separate jerk pump and injector set ups.
If choice c is selected set score to 1.
35. Which of the following best describes how metering of the fuel is accomplished in a Jerk Pump (Injection Pump)?
¡(a)Metering is done in the injectors, not the pump.
¡(b)Suction valve position is throttled.
¤(c)The effective stroke of the jerk pump is varied.
¡(d)The fuel injected is determined by a metering valve.
If choice c is selected set score to 1.
36. Which of the following is true about a "Jerk Pump"?
¤(a)Metering is controlled by adjusting the effective length of the pump stroke.
¡(b)It requuires a separate pump to lift the nozzles at the proper timing interval.
¡(c)It is named because the pump is driven directly off the reciprocating piston.
¡(d)It is usually smaller and cheaper than unit injectors because there is only one pump.
If choice a is selected set score to 1.
37. Which part of the fuel system has small, equal-sized holes that the fuel is forced through by high pressure as it enters the combustion chamber?
¡(a)The fuel pump
¤(b)The nozzle
¡(c)The metering valve
¡(d)The metering orifice
If choice b is selected set score to 1.
38. As a load is added to the diesel engine, what does the governor do?
¡(a)Increases the vacuum in the cylinders to draw more fuel & air in the cylinders
¡(b)Increase fuel before the speed drops to maintain speed
¡(c)Shed the load to another generator until the diesel speed is increased
¤(d)See the speed drop and increase fuel to bring it back up
If choice d is selected set score to 1.
39. Speed droop is defined as a decrease in
¡(a)Fuel conusmption due to lower RPM.
¡(b)Load when RPM is reduced on the engine.
¡(c)RPM prior to placing a load on the engine.
¤(d)RPM when a load is placed on the engine.
If choice d is selected set score to 1.
40. The three types of governors studied are
¡(a)Hydraulic, pneumatic, cruise control
¡(b)Mechanical, electrical, pneumatic.
¤(c)Mechanical, hydraulic, pneumatic.
¡(d)Hydraulic, electrical, mechanical.
If choice c is selected set score to 1.
41. What is the purpose of centrifugal force in mechanical type of diesel speed governor as a load is added to the generator?
¡(a)Flyweights move in and out with speed to ensure constant fuel delivery
¡(b)The generator acts as a flywheel and maintains the speed constant
¡(c)Keeps the speed constant because of the large flywheel
¤(d)Flyweights move inward as speed drops, opening up the throttle more
If choice d is selected set score to 1.
42. Which of the following best describes the purpose of an engine governor where the engine is driving an electric generator?
¤(a)Maintains constant engine speed as engine load changes
¡(b)Controls generator output voltage at varying speeds
¡(c)Maintains constant engine load as engine speed changes
¡(d)Varies the engine speed in proportion to engine load
If choice a is selected set score to 1.
If assessment score is 0% to 100% Feedback
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