selected是什么意思-沃尔特斯
试题十四
一、单项选择题：
1.
Critical speeds occurring within the operating speed range of a main propulsion diesel engine
may be changed, or have their damaging effects reduced by a/an ______.
A.
engine support vibration isolator
B.
detuner or viscous fluid damper
C.
lightened crankshaft flywheel
D.
spherically seated crankshaft bearing
2.
Precision engine bearing inserts are manufactured with a small portion of the bearing ends
extending beyond the bearing housing or caps.
The installation process of these bearings
requires sufficient ______.
A.
overlap
B.
crush
C.
lap or lead
D.
protrusion
3.
The engine has one or two group of fuel pumps, depending upon ______.
A.
the number of fuel valves
B.
the number of cylinders
C.
the speed of engine
D.
the power of engine
4.
Which of the following statements concerning the factors affecting ignition delay is correct?
A.
An increase in intake air temperature will increase ignition delay.
B.
An increase in coolant temperature will decrease ignition delay.
C.
An increase in combustion chamber turbulence will increase ignition delay.
D.
An increase in compression ratio will increase ignition delay.
5.
______providing lubricating films, oil used in marine diesel engines has to remove heat from
oil cooled piston.
A.
Except for
B.
Beside
C.
Except
D.
In addition to
6.
The ability of an oil to separate cleanly from an oil and water mixture is referred to as its
______.
A.
precipitation number
B.
neutralization number
C.
pour point
D.
demulsibility
7.
Before dismantling the pipe, would you ______the oil retained in the hose with ______?
A.
flash/fresh air
B.
wash/fresh water
C.
flush/compressed air
D.
rush/diesel oil
8.
Before “stand by” is rung on the eng
ine telegraph, it is usual to give the main diesel engine a
brief trial ______ahead and astern.
A.
with power
B.
on power
C.
with air
D.
on air
9.
A number of cylinder liners are enclosed in one cast iron casing to form a ______.
A.
cylinder cover
B.
cylinder block
C.
crankcase
D.
bed-plate
10.
Between the periods of injection and ignition of the fuel, a diesel engine crankshaft rotates
through the ______.
A.
detonation period
B.
firing period
C.
delay period
D.
advance period
11.
The turbo-blower comprises a gas turbine and a ______.
A.
condenser
B.
blower
C.
soot blower
D.
air receiver
12.
Vessel propellers are classified as being right hand or left hand. A right hand propeller turns
clockwise when viewed from ______.
A.
the bow
B.
the stern
C.
the port side
D.
the starboard side
13.
______the repair in such short time is unknown to us.
A.
How they finished
B.
How did they finished
C.
That how they finished
D.
That how did they finished
14.
In a simple mechanical governor, the ______.
A.
centrifugal force rotates the ball-head
B.
flyweight centrifugal force is balanced by spring force
C.
flyweight centrifugal force is balanced by hydraulic pressure
D.
speeder spring alone actuates the fuel control rod
15.
Wear in a cylinder liner is usually due to ______.
A.
friction
B.
abrasion
C.
corrosion
D.
all of the above
16.
A governor automatically controls engine speed by regulating ______.
A.
fuel supply
B.
firing order
C.
engine load
D.
oil level
17.
If the viscosity of the liquid being transferred remains constant as the discharge pressure
increases, the rotary pump ______.
A.
capacity will increase
B.
capacity will decrease
C.
suction pressure will increase
D.
suction pressure will decrease
18.
The purpose of the wearing rings used in a centrifugal pump is to ______.
A.
prevent an internal explosion in the pump when it is overheated
B.
enable a visual inspection of the pump while it is running
C.
insure a proper alignment of the pump coupling to the driver
D.
accommodate for friction between the impeller and the casing
19.
When a boiler is operating, the water level in the gauge glass reads ______when the boiler is
shut down.
A.
lower than
B.
higher than
C.
as much as
D.
the same as
20.
The concentration of total dissolved solids in the water of an auxiliary boiler can increase as a
result of ______.
A.
seawater contamination
B.
frequent surface blows
C.
dissolved oxygen deaeration
D.
frequent bottom blows
21.
For a purifier changing to a gravity disc with smaller hole diameter will move the interface
towards the ______.
A.
bowl periphery
B.
bowl center
C.
upper surface
D.
lower surface
22.
For a L.O. purifier, If the back pressure of the oil outlet is too high, the interface between oil
and water in the bowl will ______.
A.
be interrupted
B.
move downwards
C.
move outwards
D.
retain original
position
23.
If a bilge pump failed to build up discharge pressure, you should check for ___.
A.
excessive water in the bilges
B.
a clogged suction strainer
C.
oil in the bilges
D.
all of the above
24.
The oil
sludge is burnt in the ______onboard. I’ll show you the ashes.
A.
boiler
B.
main engine
C.
auxiliary engine
D.
incinerator
25.
A class ‘ C' fire would most likely occur in the ______.
A.
engine room bilges
B.
main switchboard
C.
paint locker
D.
rag bin
26.
If the pump for a hydraulic anchor windlass is over heating, the cause may be ______.
A.
increased pump speed
B.
excessive pump discharge pressure
C.
too low of a tilting box angle
D.
low pump speed
27.
The hand steering is a method by which the motion of the rudder is controlled with ______.
A.
a motor-driven steering wheel
B.
a pneumatic steering wheel
C.
a hand-driven steering wheel
D.
an electric steering wheel
28.
An axial piston, variable stroke pump is used in a vessel's hydraulic steering gear. Under
pressure, oil continually leaks out from between the valve plate/ cylinder barrel and will
______.
A.
cause loss of hydraulic oil from the system
B.
result in extreme damage to the pump
C.
cause damage to the pump if not continually drained from the pump casing
D.
result in the system high side pressure to substantially drop off
29.
With reference to operating a four-ram steering gear system under emergency conditions,
which one of the following statements is incorrect ?
A.
Only one pump should be used at any time
B.
The ship speed should be reduced to 70% of the normal
C.
Watch keeping of the steering gear should be increased
D.
Limitations of the steering gear should be logged but the bridge need not be informed
30.
Which of the following problems could cause air to blow out through the inlet air filter of a
running compressor?
A.
Excessive compression in the cylinder
B.
A broken intake valve
C.
A dirty inlet filter element
D.
An improperly adjusted
discharge valve
31.
When a refrigeration compressor is in the 'off' cycle, the thermal expansion valve will ______.
A.
always be wide open when the compressor restarts
B.
continue to operate as if the system were in operation
C.
remain open until evaporator pressure equalizes, then close until the compressor restarts
D.
always be completely closed until the compressor restarts
32.
An increasing head pressure in a refrigeration system, without any corresponding change in
the cooling water inlet temperature, would probably be caused by ______.
A.
restriction in refrigerant piping
B.
air and non-condensable gases in the condenser
C.
water in the refrigerant
D.
flooding back of liquid refrigerant from the evaporator
33.
In a refrigeration system, if the cooling water to the condenser fails, the ______.
A.
box temperature solenoid valve will close
B.
expansion valve will close
C.
compressor will shutdown
D.
king valve will open
34.
The basic training in fire prevention and fire fighting should include the theoretical elements
which should cover ______.
A.
the three elements of fire and explosion
B.
lower and upper flammable limits
C.
classification of fires and applicable extinguishing agents
D.
all of the above
35.
Sacrificial zinc anodes are used on the saltwater side of diesel engine heat exchangers to
______.
A.
reduce electrolytic action on heat exchanger metals
B.
keep heat transfer surfaces shiny and clean
C.
prevent rapid accumulation of marine growth
D.
provide a protective coating on heat exchanger surfaces
36.
To parallel an incoming machine to a running machine therefore it is necessary to ensure
firstly that ______.
A.
two frequencies must be brought into phase
B.
the incoming machine accepts a small amount of load
C.
the running machine must be unload
D.
both voltages are equal
37.
Self-
excited a.c. generator with ‘error operated’ voltage control systems draw the full
excitation power for the machine terminals. This dispenses with the current transformers,
reactors and capacitors necessary for accurate compounding, but renders the excitation system
vulnerable to variations in its output voltage. Which of the following is correct about the
generator mentioned according to the sentences above?
A.
It consumes no excitation power.
B.
It has current transformers.
C.
Components are needed for accurate compounding.
D.
Its excitation system is vulnerable to voltage variations
38.
Which of the following should be the FIRST step in removing a generator from parallel
operation?
A.
Trip the generator off the switchboard.
B.
Turn off all electrical equipment.
C.
Remove the load from the 'off going' generator.
D.
Increase the cycles of the generator staying on the line.
39.
This arrangement is ______if the elements are directly connected to one another and the
control action takes place without human involvement.
A.
a manual closed loop
B.
a manual opened loop
C.
an automatic closed loop
D.
an automatic opened loop
40.
The viscosity regulator controls the fuel oil temperature ______provide oil at the correct
viscosity for combustion.
A.
in order that
B.
because of
C.
in order to
D.
owing to
41.
______is a precaution which contributes to avoiding trouble under normal operating
conditions.
A.
Constant inspection
B.
Keeping constant load
C.
Remaining constant temperature
D.
varying speed
42.
To repair a small electrical motor that has been submerged in saltwater, you should ______.
A.
wash it with fresh water and apply an external source of heat
B.
renew the windings
C.
send it ashore to an approved service facility
D.
rinse all electrical parts with a carbon tetrachloride cleaning solvent and then blow dry the
motor with compressed air
43.
The diesel engine consumes considerably less fuel than the steam engine for equal output,
______enables a motor-ship to load more cargo.
A.
why
B.
which
C.
in which
D.
on which
44.
The conclusion that mechanical efficiency is always ______100 per cent is correct.
A.
small than
B.
more than
C.
little than
D.
less than
45.
The diesel engine valve subjected to most severe conditions of service is the ______.
A.
cylinder exhaust valve
B.
air starting valve
C.
air inlet valve
D.
cylinder
relief valve
46.
One cylinder of a diesel engine is persistently knocking and does not cease when the fuel
supply to that cylinder is secured. Which of the following problems may be the cause?
A.
Low loading of the cylinder.
B.
Excessive cooling of that piston.
C.
Sluggish ring action on the piston.
D.
A mechanical defect in a working part.
47.
A diesel engine is operating with excessively high exhaust temperatures at all cylinders. To
correct this condition, you should first ______.
A.
reduce the engine load
B.
increase the cooling water flow
C.
increase the lube oil pressure
D.
adjust the fuel rack
48.
High exhaust temperature and black smoke exhausting from an auxiliary diesel engine can be
caused by ______.
A.
engine overload
B.
low combustion temperature
C.
plugged fuel nozzle holes
D.
excessive compression pressure
49.
Hearing a strong noise, ______at once.
A.
the engine stopped
B.
the engine was stopped
C.
he stopped the engine
D.
he had stopped the engine
50.
To correct a hunting problem in a main propulsion diesel engine hydraulic governor, you
should ______.
A.
increase the governor oil pressure
B.
adjust the speed droop setting
C.
adjust the speeder spring travel
D.
adjust the compensating needle valve
51.
The reciprocating pump can’t draw water from a tank may be caused by ______.
A.
leaky pipe
B.
opened inlet valve
C.
too much water in tank
D.
None of the
above
52.
Diesel engine exhaust temperatures may be used to indicate ______.
A.
leaking exhaust valves
B.
an overloaded cylinder
C.
a clogged injector nozzle
D.
all of the above.
53.
It is well known that the whole power distribution of the ship’s electrical services mainly
depend on the ______.
A.
sub-boards
B.
main switchboards
C.
emergency switchboards
D.
distribution
boards
54.
A main propulsion diesel engine is normally shut down by ______.
A.
shutting off the air supply
B.
over-speeding the engine
C.
securing the fuel supply
D.
securing the ignition system
55.
Oil mist detectors are usually used on board to detect oil mist density within ______.
A.
the engine crankcase
B.
the engine scavenge boxes
C.
drain tanks
D.
fuel tanks
selected是什么意思-沃尔特斯
selected是什么意思-沃尔特斯
selected是什么意思-沃尔特斯
selected是什么意思-沃尔特斯
selected是什么意思-沃尔特斯
selected是什么意思-沃尔特斯
selected是什么意思-沃尔特斯
selected是什么意思-沃尔特斯
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