Motor Engineering – MEO CLASS 4 MMD PAPER

91. In a uniflow scavenged marine 2-stroke diesel engine, the scavenge ports in a cylinder liner are machined
    1. Only for a part of the circumference, at an angle almost tangential to the circumference of the liner
    2. All around the circumference at right angles to the circumference of the liner
    3. only for a part of the circumference, at right angles to the circumference of the liner
    4. All around the circumference at an angle almost tangential to the circumference of the liner

ANS.: D

92. If the tappet clearance between the rocker arm tappet and exhaust valve stem is excessive then:
    1. The valve will open early and close later
    2. The valve will open later and close early
    3. The valve will open and close later
    4. The valve will open and close early

ANS.: B

93. In order to reduce thermal loading on the upper part of the liner and increase the effectiveness of cylinder lubrication, modern 2-stroke marine diesel engines are designed to have:
    1. Cermet coated piston rings, bore cooled liners and uniflow scavenging
    2. High top land of piston crown and deeper cylinder cover with top land of crown extending into cylinder cover at TDC
    3. Low top land of the piston crown with bore cooled cylinder liner
    4. Bore cooled cylinder liner and bore cooled piston crown with torroidal shape combustion chamber

ANS.: B

94. Which of the following conditions can lead to reduced power developed by a main engine?
    1. High scavenge air temperature
    2. Choked air suction filter of a turbocharger
    3. Blow past in one or more units
    4. All of the above

ANS.: D

95. Which of the following types of diagrams would give an indication of effectiveness of exhaust and scavenge processes?
    1. Power card
    2. Draw card
    3. Light spring diagram
    4. All of the above

ANS.: C

96. The arrangement used to protect overheating of the superheaters under fluctuating loads is called
    1. De-superheater
    2. Attemperator
    3. Steam dumping valve
    4. Feed heater

ANS.: B

97. Piston rod stuffing box scraper rings butt clearances should:
    1. Not to be allowed to fall below 50% of original clearance
    2. Not to be allowed to increase above 50% of original clearance
    3. Not to be allowed to fall below manufacturer recommended value
    4. Not to be allowed to increase above manufacturer recommended value

ANS.: C

98. In a 2-stroke engine a ________________ separates the under piston space from the crankcase.
    1. A-frame
    2. Crosshead
    3. Diaphragm
    4. Scavenge space

ANS.: C

99. Fusible plugs are installed in fire-tube boilers to
    1. provide a means of draining the boiler
    2. warn the engineer of low water level
    3. cool the crown sheet at high firing rates
    4. open the burners’ electrical firing circuits

ANS.: B

100. Which of the following gauges are generally used to evaluate main bearing clearances?
     1. Poker gauge
     2. Feeler gauge
     3. Telescopic feeler gauge
     4. Dial gauge

ANS.: C

101. In a coil-type auxiliary water-tube circulation boiler
     1. unevaporated feedwater collects in the bottom of the flash chamber
     2. all generated steam is recirculated through heating coils in the boiler
     3. heated water flashes to steam in the boiler heating coils
     4. response to steam demand is slower than in a fire-tube boiler

ANS.: A

102. For a continuous operation diesel engine, a duplex filter unit would be the bestarrangement because
     1. changing filter elements would not interrupt engine operation
     2. filtering occurs twice in each pass of oil through the system
     3. clogging will not occur
     4. dropping pressure is half of that through a single filter unit

ANS.: A

103. As per regulations, within how many hours before each departure, satisfactory working of the steering gear must be checked?
     1. 2
     2. 12
     3. 24
     4. None of the above

ANS.: B

104. Modern 4-stroke medium speed, marine diesel engine exhaust valve spindles are rotated by providing
     1. Nozzle rings
     2. Tappet clearance
     3. Spinners or vanes
     4. Rotocaps

ANS.: D

105. The purpose of economizer is to:
     1. Decrease the capacity and size of the auxiliary boiler
     2. Cooling down the exhaust gases in order to reduce NOx emission
     3. Allowing Sox to react at low temperatures with water to form acids thus reducing Sox emission
     4. Increasing the overall efficiency of the main propulsion plant

ANS.: D

106. Microbiological growths in marine fuel are a common occurrence that can beuscg
     1. extremely detrimental to equipment and operating processes
     2. prevented by maintaining proper storage temperatures
     3. removed from emulsified fuel oil during the centrifuging processes
     4. All of the above are correct

ANS.: A

107. The function of the tie rods is to:
     1. Keep the engine components under tension at all the times
     2. Just secure the engine parts together
     3. Act as holding down bolts for the bedplate and keeps all the engine components together
     4. Keep engine components under high compression, so that tensile stresses acting during firing stroke do not exceed this pre-compression to avoid fatigue failure

ANS.: D

108. Which of the following types of crankshafts is much lighter at similar power requirements?
     1. Fully built type
     2. Semi built, all welded type
     3. Semi built type
     4. Solid forged type

ANS.: B

109. After an engine has been started using a Bendix drive unit, the drive gear, or pinion disengages  from the flywheel due to
     1. the action of a spring
     2. rotation of the starting cam
     3. the higher rotating speed of the flywheel
     4. accumulator pressure

ANS.: C

110. Fuels as produced in a refinery are generally sterile, however, contamination can occur as fuels are
     1. stored at the refinery
     2. stored on the vessel
     3. transported to the distribution sites
     4. All of the above are correct

ANS.: D

111. Which of the following statements is false?
     1. Excessive cylinder liner lubrication can aggravate scuffing.
     2. Use of anti polishing ring reduces scuffing.
     3. Deep honing of liner fails to give an ideal liner surface
     4. None of the above

ANS.: D

112. In a fully built or semi built type crankshaft, how can any slippage at shrink fit be identified?
     1. By inspecting the locking arrangement provided
     2. By checking the dowel provided.
     3. By checking the witness mark provided for reference .
     4. By checking the performance of the engine

ANS.: C

113. Which of the following is one of the major advantages of resin choking over cast iron choking, in holding down arrangements of modern diesel engines?
     1. Better vibration damping properties.
     2. Better compressive strength
     3. 100% contact, no need for surface preparation
     4. None of the above

ANS.: C

114. In a 2-stroke crosshead type of engine, the side thrust generated due to rolling and connecting rod and fore-aft thrust due to pitching motion of the ship is taken care of by the: ( also asked in 2 stroke trunk piston type how thrust transmitted ans is piston and liner )
     1. Piston and the liner
     2. Connecting rod and the piston rod
     3. Crosshead shoes and guides
     4. Crankpin and thrust bearing

ANS.: C

115. In a VIT equipped jerk type fuel pump:
     1. Raising the barrel delays beginning of injection
     2. Lowering the barrel delays beginning of injection
     3. Raising the barrel delays end of injection
     4. Lowering the barrel delays end of injection

ANS.: A

116. The over speeding of the diesel engine driving an electric generator could cause uscg 145
     1. low voltage trip to trip
     2. reverse power trip to trip
     3. damage to windings
     4. excessive exhaust temperatures

ANS.: C

117. In a large, slow-speed, main propulsion diesel engine, which of the parts listed is under tension when the engine is running?
     1. Bed plate
     2. Column
     3. Entablature
     4. Tie rod

ANS.: D

118. A diffuser is provided at the end of a mechanical atomizer in boiler onboard
     1. To prevent blow back of the flame
     2. To mix the air and fuel properly
     3. To prevent blow out of the flame
     4. To eject the excess fumes from the atomizer

ANS.: A,B

119. Steam stop valve is eased of its seat during boiler start up from cold
     1. To allow thermal expansion of parts
     2. To allow steam flow during start up
     3. To prevent water hammer
     4. All of the above

ANS.: A

120. Which of the following statements about the design of D- type boilers, is false ?
     1. The heavier water in top drum flows back to the bottom drum through the down- comers outside the furnace
     2. Inside the furnace the water is heated up in the risers
     3. The upper drum is the steam/water drum and the lower one is the water drum.
     4. The feed water is pumped into the lower drum

ANS.: D