21. The advantage of tie rods over an engine without tie rods is that:
A. The engine is very easily aligned after any misalignment has taken place between different components of the engine
B. The engine doesn’t require thrust pads for transmission of thrust to the ship’s hull as the same is being taken care of by the tie rods
C. The engine components are much lighter leading in overall reduction is engine weight with a high power generation with the elimination of fatigue stresses
D. There are no advantages of engines with tie rods, because tie rods require regular maintenance and replacement like connecting rods and overall engine becomes more expensive to operate
22. It is a known fact that centrifugal pumps require priming for pumping liquids, as they cannot handle air and will lose suction due to air entry . But on the other hand T/Cs use centrifugal compressors for supercharging. Which of the following do you think makes a centrifugal compressor to pump air and behave differently than the centrifugal pumps?
A. Presence of air cooler
B. Presence of Labyrinth seal
C. High speed of rotation, very fine internal clearances and large impeller diameters
D. Difference in principle of operation
23. 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
24. What is meant by elastohydrodynamic lubrication?
A. Formation of hydrodynamic film under high pressure with minor elastic deformation of mating surfaces, distributing load over a greater area
B. Addition of extreme pressure additive (EP) to the lubricant
C. Addition of Viscosity index improvement additive
D. Addition of elastomer based additives
25. Which of the following statements is false?
A. Oxidation of lubricant leads to decrease in its viscosity
B. Formation of oxidation acids, sulfuric acid leads to depletion of TBN of lubricant
C. Contamination with water will lead to decrease in the load carrying capacity of a lubricant.
D. Buildup of insolubles will lead to increase in viscosity of a lubricant
26. Which of the following is a reasonable statement about water washing of turbine side of a T/C ?
A. It leads to thermal shock and reduces the life of the T/C
B. It leads to thermal shock and not so effective as solid washing
C. If properly carried out keeping rpm, load, temperature limits & other factors into account; it is quite safe and more effective than solid washing
D. It should never be carried out as most of the engine manufacturers recommend against the same
27. Fins are installed on the generating tube surfaces in waste heat boilers to
(A) Prevent soot fires in the exhaust system
(B) Prevent exhaust gas erosion of the tubes
(C) Increase the velocity of exhaust gas flow
(D) Increase the rate of heat transfer
28. Which of the following conditions is responsible for the fuel oil to atomize when using a steam atomizer in an auxiliary 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.
29. After prolonged operation, jerk type fuel pumps wear on the top edge of plunger and edges of spill ports and helix due to erosion by high pressure fuel as it spills. This wear would result in
A. Late start of injection and early end of injection
B. Early start of injection and late end of injection
C. Early start of injection and early end of injection
D. Late start of injection and late end of injection
30. Which standards govern the specifications for supply of Residual Marine Fuels and
Distillate Marine Fuels onboard merchant ships?
A. ISO 3012:1999
B. ISO 3648:1996
C. ISO 8216-1:2010
D. ISO 8217:2010