Motor august online questions

MOTOR AUGUST 2013

WHICH OF THE FOLLOWING IS NOT ADDED FOR TREATMENT FOR COOLING WATER IN A CENTRALLY COOLED F.W SYSTEM AS IT IS CARSIOGENIC?? DONT REMEMBER THE OPTIONS FOR THIS 1!!!

•        What is the viscosity of fuel at the time of ignition

•        10-30cst

•        50cst

•        180cst

380cst

•        Chain can deform how

•        Due to plastic deform

•        Due to elastic deform

•        Due to wear on bushes nd pins

 None of the above

11. which of the following would normally  be a consequence of retarding fuel injection timing?

a.increased maximum combustion pressure

b.decreased maximum combustion pressure

c.increased compression pressure

d.decreased compression pressure

in the ………… type of t/c 2/s diesel engine is …………… to start.<mandatory>

a.constant,easier

b.constant,difficult

c.pulse,difficult

d.none

. in 2s diesel engine …………type of t/c have inability to start.To overcome this ………..is provided in engine.

a.constant,engine driven blower

b.constant,electrically operated aux blower

c.pulse,electrically operated aux blower

d.pulse,mechanically driven blower

24.The labirynth seal provided on the tubine side of t/c

a.protects contamination of lube oil wid exhaust gas

b.help to cool the turbine

c.help to cool the shaft

d.protects the sump oil to get sucked by exh gas

.sealing on turbine side of t/c is been done by

a.grease oil

b.cup oil

c.labyrnth seal.

d.none

If the combustion control system of an automatically fired auxiliary boiler fails to sustain burner ignition after a normal shutdown, you should check for a/an
A. faulty photocell detector B. low steam pressure C. high voltage on the ignition electrode D. open air damper

Steam temperature control for the ESD boiler is achieved by :
A. Fitting a de-superheater between 1st & 2nd passes of superheater B. Fitting an attemperator between 1st & 2nd passes of superheater C. Gas dampers in boiler uptake D. Bypassing the superheater

Which of the following functions is done by a cam operating an exhaust valve ?
A. It governs the timing of opening and closing of the valve . B. It governs the speed at which the valve operates C. It governs the amount of opening of the valve D. All of the above

What do you mean by surge limit of a turbocharger ?
A. Characteristic curve of a turbocharger B. Portion of compressor characteristic curve which lies on the left side of the point of maximum pressure C. A line joining all the points of maximum pressure on compressor characteristic curves , drawn at various speeds of operation D. Maximum rpm limit of T/C above which surging will start

Which of the following conditions is responsible for the fuel oil to atomize when using a steam atomizer in anauxiliary boiler?
A. Expansion of the steam in the furnace. B. Expansion of the steam in the whirling chamber. C. Expansion of the steam in the orifice plate. D. All of the above.

labyrinth seal fitted on the back surface of a compressor wheel of a turbocharger:
A. Prevents bearing lube oil contamination B. Prevents bearing lube oil being sucked into the air stream C. Helps to keep the shaft cool by controlled leakage of air D. None of the above

Even if there is an oil mist concentration inside a crankcase, and there is also a hot spot, crankcase explosion will only take place when_________________
A. The hot spot provides the ignition temperature for the oil mist concentration B. When the oil mist - air mixture is in the flammable range C. Both A and B D. None of the abov

Irregular circumferential wear of liner due to diminishing neutralizing capacity of cylinder oil away from lubricating holes is known as:
A. Micro seizure B. Scuffing C. Scoring D. Clover leafing

Which of the following statements correctly describes the phenomenon of surging in a 2-stroke crosshead type engine?
A. Due to sudden increase in engine load the exhaust gases may flow back through scavenge ports causing surge B. Due to sudden decrease in engine load the turbocharger pressure ratio drops . This causes high pressure downstream of T/C in scavenge trunk causing flow reversal of scavenge air C. Due to sudden increase in engine load , the T/C turbine rpm may increase suddenly increasing the compressor pressure ratio to surge D. Due to sudden decrease in engine load , the turbocharger may stall as the higher pressure downstream in exhaust system may cause reversal of flow of exhaust gases

 22)   If the valve tappets in a diesel engine are set at greater clearances than those specified by the engine manufacturer, those valves will

a)open late and close early b)open late and close late

c)fail to open when the engine is cold d)fail to open at normal operating temperature

. In order for microbiological growths to thrive in a fuel tank it is necessary for

A. high temperatures to exist

B. low temperatures to exist

C. small amounts of water to be present

D. large amounts of water to be present

8. The purpose of an air cooler in a supercharging system is to:

A. Reduce temperature of supercharged air in order to condense and remove maximum possible moisture from the air prior entry to the engine

B. Reduce the temperature of the supercharged air in order to increase the density & also to cool down below dew point to remove moisture from air prior entry to the engine

C. Cool supercharged air to increase its density such that the dew point is not reached to avoid entry of moisture into the engine

D. Cool supercharged air to increase it???s density and also to keep the peak temperature and exhaust gas temperature within limits

Even if there is an oil mist concentration inside a crankcase, and there is also a hot spot, crankcase explosion will only take place when

A. The hot spot provides the ignition temperature for the oil mist concentration

B. When the oil mist - air mixture is in the flammable range

C. Both A and B

Labyrinth seal fitted on the back surface of a compressor wheel of a turbocharger:   

A. Prevents bearing lube oil contamination

B. Prevents bearing lube oil being sucked into the air stream

C. Helps to keep the shaft cool by controlled leakage of air

D. None of the above

The primary function of a flame safeguard system, as used on an automatically fired auxiliary boiler, is to prevent

A. accidental dry firing and overpressure

B. uncontrolled fires in the furnace

C. explosions in the boiler furnace

D. explosions in the boiler furnace

External fouling of boiler tubes can lead to:

A. Greater steam generation

B. Tube corrosion

C. Tube Erosion

D. Protection of tube against corrosion

Which of the bearings listed is most widely used for main and connecting rod bearings of modern diesel engines?

A. Steel-lined

B. Poured babbitt, self-aligning

C. Split roller

D. Precision insert

Prompt correction of speed of diesel engines driving alternators, without having massive fluctuations is ensured by incorporating:

A. Load limiting devices

B. Load sharing devices

C. Load sensing devices

D. Load shedding devices

As per regulations, within how many hours before each departure, satisfactory working of the steering gear must be checked?

A. 2

B. 12

C. 24

D. None of the above

In a fully built or semi built type crankshaft, how can any slippage at shrink fit be identified?

A. By inspecting the locking arrangement provided

B. By checking the dowel provided.

C. By checking the witness mark provided for reference .

D. By checking the performance of the engine

. In a VIT equipped jerk type fuel pump:

A. Raising the barrel delays beginning of injection

B. Lowering the barrel delays beginning of injection

C. Raising the barrel delays end of injection

D. Lowering the barrel delays end of injection

Which of the following factors affect penetration of fuel droplets during injection?

A. Quality of atomization

B. Injection temperature

C. Scavenge air pressure

D. All of the above.

As a thumb rule, ovality in crankpins of medium speed engines should not exceed _____________ of bearing clearance.

  A. 10%

B. 15%

C. 25%

D. 30%

Improper maintenance of an automatic auxiliary boiler oil burner could result in

  A. fuel pump failure

B. fan motor failure

C. increased feedwater consumption

D. decreased boiler efficiency

In which of the following steering modes, rudder will be locked at a particular angle until next manual order?

  A. Follow up

B. Auto pilot

C. Non Follow up

D. None of the above

As per regulations, the torque capacity of a steering gear system should be such so as to be able to turn the rudder__________________________

A. 35 degrees one side to 35 degrees on the other side at maximum service speed

B. 35 degrees one side to 30 degrees on the other side at maximum service speed

C. 35 degrees one side to 35 degrees on the other side at normal service speed

D. 35 degrees one side to 30 degrees on the other side at normal service speed

exh vv spring air pressure

-3 bar

-5 bar

-7 bar

-20-25 bar

1.      Which of the following actions should normally be taken during each watch when the auxiliary boiler is in operation?

A.    Clean the flame scanner photocell window.                    

B.     Inspect and clean all solenoid valves.                  

C.     Lift the safety valves by hand.                            

Inspect for oil or water leaks.

1.      Unit of kinematic viscosity

A.    centipoises

B.     centistokes

C.     CCAI

D.    none of above

1.      Exhaust valve seat material

A.    stainless steel,

B.     invar,

C.     nimonic

income

1.      In case of cross scavenged engines :
A. The exhaust ports are located above the scavenge ports and they open everytime the piston reaches near TDC and near BDC
B. The exhaust ports are located below the scavenge ports and they open everytime the piston reaches near TDC and near BDC
C. The exhaust ports are located above the scavenge ports and they open everytime the piston reaches near BDC
D. The exhaust ports are located below the scavenge ports and they open everytime the piston reaches near BDC

Clearance volume scavenging in a turbocharged, four-stroke/cycle diesel engine is accomplished

a) during the valve overlap period

b)with only the exhaust valve open

c)at a pressure below atmospheric

d)without cooling the cylinders or pistons

the 2s m.e works on which therotical cycle

-joule cycle

-diesel cycle

-dual cycle

-none of the above

1.      Besides raising the liner wall temperature to sulphur corrosion

a.       Increase cylinder feed

b.      Increase scavenge air temperature

c.       Improved separation of water 

d.      All the above

1.      Resin chokes

a.       Better vibration damping

b.      Better compressive strength

c.       Unaffected by fuel oil and sea water chemicals

d.      None of the above.

Shims are added to the fuel pump

A.retarding injection

B.Advancing injection

1.      Which steering gear type is electro hydraulic?

i.  Ram type

ii.Rotary type

iii.                      Both

iv.                      None

A normal manometer reading of turbocharger air suction filter and normal speed of the turbocharger but reduced scavenge air pressure may be due to:

A. Fouling of the nozzle ring

B. Fouling of diffuser or compressor wheel

C. Fouling of the turbine

D. Cold climate

Which of the following can be a consequence of worn scraper rings and sealing rings of a piston rod stuffing box?

A. Increased risk of scavenge fire

B. Increased risk of crankcase explosion

C. Increased Lube oil consumption

D. All of the above

The super long stroke slow speed 2-stroke diesel engines when compared to short stroke version gives:

A. Poorer propulsive efficiency but better fuel combustion

B. Better propulsive efficiency but poorer fuel combustion

C. Better propulsive efficiency as well as better fuel combustion

D. Poorer propulsive efficiency as well as poorer fuel combustion

In modern 2-stroke marine diesel engines the exhaust valves are:

A. Mechanically actuated

B. Pneumatically actuated

C. Hydraulically actuated

D. Electrically actuated

Economisers are built up with

A. Copper tubes

B. Plain steel tubes

C. Stainless steel tubes

D. Steel tubes fitted with shrunk on C.I. grills

 non water-cooled turbocharger offers which of the following advantages?

A. More heat is available for waste heat boilers

B. Corrosion problems of internal surfaces due to formation of sulfuric acid are eliminated

C. Improved thermal efficiency of turbocharger

D. All of the above.