3) Cleaned the needle valve tip carefully ( ) brushing away the carbon.
(a) in (b) of (c) together (d) by
4) The (1) the compression pressure in a cycle the (2) the efficiency of the cycle.
(a) 1-higher, 2-lower (b) 1-higher, 2-greater
(c) 1-lower, 2-greater (d) 1-greater, 2-higher
5) The movement of the power piston in a hydraulic governor is controlled by which of the following ?
(a) The movement of the pilot valve (b) The movement of the accumulator
(c) The pressure of the power oil (d) The position of ther flyweights
6) Diesel engine can be quickly brought to a stop although at first sight, the reverse might be expected when the effect of a heavy flywheel is considered. Which of the following would be correct meaning ?
(a) Diesel engines can be quickly reversed
(b) Diesel engines can be stopped quickly
(c) A stop of diesel engines are widely effected by a heavy flywheel
(d) Diesel engines can be easely reversed considering the effect of a heavy flywheel
7) Which of the following will insure smooth engine operation ?
(a) even fuel delivery to each cylinder (b) equal power impulses in each cylinder
(c) correct fuel rack adjustments (d) having manifold runners the same length
8) When a supercharger is fitted to a diesel engine, ( )
(a) the clearance volume is increased to keep the maximum firing pressure approximately the same as a natutally aspirated engine
(b) the normal valve timing of 30 to 40 degrees is not changed on a four-cycle engine
(c) the inlet air temperature remains approximately the same
(d) the exhaust manifolds are usually water-cooled
9) The continual fluctuation of the engine from the required speed even when the load does not change is ( )
(a) hunting (b) sensitivity (c) speed drop (d) promptness
10) What does the term "Timed for port opening" refer to in diesel engine fuel injection systems ?
(a) The time of fuel injection during port opening period.
(b) Injection is timed to start with port opening
(c) The end of injection is timed with port opening period
(d) The end of effective injection stroke is varied according to the port opening
11) The ( ) point is the temperature at which the oil will continue to burn when ignited.
(a) explosion (b) flash (c) fire (d) ignition
12) What is the instrument of studying the effects of valve setting and the work that is done per stroke?
22) The rate at which work is done by the expanding gases in pushing the piston downward is called ( ) horse power.
(a) indicated (b) shaft (c) nominal (d) brake
23) For practical purposes ( ) is determined by noting the number of seconds required for a given quantity at a particular temperature to flow through a standard orifice.
(a) density (b) pour point (c) flow ratio (d) viscosity
24) The sequence of order in which power impulses occur in an engine is called the ( ).
(a) expansion order (b) crank angle (c) ignition point (d) firing order
25) Cyclic speed variations occur in a diesel engine operating under a constant load because the engine ( ).
(a) pistons tend to increase engine speed on the power strokes and reduce it on compression strokes
(b) cylinders do not develop the same power
(c) governor is not operated
(d) all of the above
26) In a two stroke cycle engine, the ( ) opens and closes the scavenging port.
(a) piston (b) slide valve (c) rocker arm (d) valve
27) Which of the following is not the internal combustion engine ?
30) On some diesel engines, the energy of the exhaust gases is employed to drive a centrifugal compressor which precompresses the cylinder(1). Such a device is known as a (2). and appreciably increases the (3). of diesel engine
(a) 1-air, 2-supercharger, 3-input.
(b) 1-air, 2-turbo supercharger, 3-input.
(c) 1-charge, 2-turbine, 3-output.
(d) 1-charge, 2-turbo supercharger, 3-output
31) In a machine, however simple, the moving parts would wear and become hot if they were not ( ).
(a) fitted (b) cooled (c) operated (d) lubricated
32) The inability to change the speed when a new load requires such a change is called ( )
(a) hunting of governor (b) overspeed of governor
(c) stability of governor (d) dead beat of governor
33) A ( ) is an instrument used to measure temperatures higher than those which can be measured by mercurial thermometers.
39) The time between fuel injection and ignition in a diesel engine is known as ( )
(a) injection lag (b) ignition lag (c) detonation lag (d) precombustion lag
40) In dressing down a too-tight ring, the ring should be rubbed on ( )
(a) mica paper (b) emery paper (c) cylinder (d) ginder
[외연기관 40문항]
41) In order for steam to pass through a turbine, it must have a residual velocity when leaving the turbine. This kinetic energy of this residual steam velocity represents a loss, which is called ( ).
(a) throttling loss (b) leaving loss (c) work loss (d) heat loss
42) Measured wear of the rotor bearings on h.p turbine with ( ).
62) Special types of periscopes are fitted to boilers to observe ( ).
(a) smoke going out the stack (b) oil atomization in the furnace
(c) combustion gases entering the uptake (d) water level in the boiler
63) Excessive corrosion will occur on the internal surfaces of economizers if ( ).
(a) deaeration in the feed system is not effectively accomplished
(b) soot accumulation is not properly removed by effective use of soot blowers
(c) the burner equipment is not performing efficiently and incomplete combustion is taking place
(d) any of the above
64) The auxiliary exhaust steam is used to ( ).
(a) heat the fuel oil (b) drive the bilge pump
(c) heat the feedwater (d) drive small auxiliaries
65) Throttling loss result in ( )
(a) high steam enthalpy at the first stage nozzles
(b) low steam enthalpy at the first stage nozzles
(c) low steam enthalpy of steam leaving the last moving blades
(d) high steam enthalpy of steam leaving the last moving blades
66) The function of the air pump is to remove the air and condensed steam from condenser, so that the condenser can continuously produce the desired ( )
(a) pressure (b) condensate (c) temperature (d) vacuum
67) The second stage of the main steam air-rejector is used to bring the propulsion
turbines ready for port to
(a) simplify the starting produce (b) reduce steam losses
(c) decrease the warm-up time period (d) decrease the axial clearance
68) The steam, in forcing its way up through the scum, produces ( ).
(a) frothing (b) water hammer action (c) scale (d) boiling
69) What color flame indicates efficient combustion in boiler?
(a) A reddish flame (b) An incandescent white flame with jagged edges
(c) Smoky flame (d) Yellowish orange rolling flame
70) To assist in equalizing the loads on the gear teeth, there is a ( ) with flexible couplings connecting the first reduction gear to the second gear.
89) A circuit that has one wire in contact with the hull of the ship is a ( ).
(a) closed circuit (b) short circuit (c) grounded circuit (d) open circuit
90) The ( ) is an induction machine, that is, it operates on the principle that when a conductor cuts a magnetic flux, a voltage is induced in it and current to a closed circuit.
118) Three-phase transformers are not used aboard ship because ( ).
(a) if one phase opens, it gives no power
(b) they are heavier in weight in capacity output
(c) they are too expensive
(d) they are too complicated
119) A "dead front" switchboard is a board with ( ).
(a) no switches in it (b) insulated switches and no open terminals
(c) no circuit breaker on it (d) no safety wooden handrail or rubber mat
120) Storage batteries are not allowed to be stored in the ( ).
(a) radio shack (b) pump room (c) engine room (d) any of the above
[보조기계 40문항] (121-160)
121) When making repairs to a refrigeration system, which of the following safety precautions is not necessary?
(a) ventilate area (b) keep flame and open light away
(c) have O.B.A. available (d) wear goggles
122) Some causes of a noisy compressor are ( ).
(a) too much oil in crankcase (b) slugging due to flooding back of refrigerant
(c) worn bearings, pins, etc (d) any of the above
123) A freon compressor will start automatically when ( ).
(a) the solenoid valve closes (b) the expansion valve closes
(c) the expansion valve opens (d) the solenoid valve opens
124) If the compressor short-cycles on the high-pressure cutout, which of the following would you check?
(a) check for too much refrigerant in the system
(b) be sure system is getting cooling water
(c) if plenty of cooling water is running through but it is not picking up heat, the condenser tubes need cleaning
(d) all of the above
125) A double-trunk piston is used to ( ).
(a) prevent gas from getting to crankcase (b) prevent oil from mixing with the refrigerant
(c) absorb some of the side thrust (d) all of the above
126) In order to avoid excessive heat stress, the temperature difference of the incoming and outgoing water should be about ( )℉ in small and medium sized engine.
(a) 20 (b) 50 (c) 70 (d) 100
127) A gear wheel making 156 rpm has 56 teeth. It drives another gear at 91 rpm. The number of teeth on the second gear is ( ).
(a) 66 (b) 75 (c) 96 (d) 85
128) What is it that changes the temperature of substance without changing the form?
149) If a compressor runs continuously, the probable cause is ( )
(a) faulty cooling water valve (b) insufficient refrigerant
(c) a clogged condenser (d) any of the above
150) In the discharge line between the compressor and the condenser, one would find ( )
(a) high pressure, low temperature liquid
(b) high pressure, high temperature gas
(c) high pressure, high temperature liquid
(d) high pressure, low temperature gas
151) The valve which shuts off a liquid line with the least amount of resistance to flow is the ( ).
(a) gate valve (b) check valve
(c) globe valve (d) safely valve
152) Intercooling of a multistage air compressor has the advantages of reducing the work of compression on the succeeding stages and ( ).
(a) condensing part of the original water vapor content
(b) reducing the maximum piston loads
(c) increasing the volumetric efficiency
(d) all of the above
153) The dehydrator is used ( ).
(a) to remove air from the system (b) to remove moisture from the system
(c) when adding refrigerant to the system (d) (b) and (c)
154) Heat added to a substance without causing a change of state will cause an increase in temperature. This heat is called ( )because its addition is perceptible on the thermometer.