Q-An emergency diesel generator cooling system is equipped with an automotive type thermostat. If the thermostat bellows loses its charge, the thermostat will __________.
A) open, and the coolant temperature will increase
B) open, and the coolant temperature will decrease
C) close, and the engine coolant temperature will increase
D) close, and the coolant temperature will decrease
Q- deep well cargo pump are used in
a. chemical tanker
Q-Why is it essential to renew turbocharger bearings after a preset number of hours of running even if the bearings are in seemingly perfect condition?
A. Because they are prone to failure due to prolonged exposure to high temperature conditions.
B. Because they are subject to cyclic loading and are prone to failure due to metal fatigue.
C. It is not essential to renew if condition monitoring suggests perfect condition.
D. Lube oil contamination is bound to occur and affect the condition of the bearings
Answer-B (Because bottom end bearing bolts are max amount of fatigue stress)
Q- A D/E with full speed rpm of 1000 drives a propeller at 300 r.p.m...what is speed reduction ration?
a)0.3 to 1
b)3.33 to 1
c)33 to 1hde
d)300 to 1
Q- Labyrinth seal fitted onthe back surface of a compressor wheel of a turbocharger
a) prevents bearing lube oil contamination
b) prevents bearing lube oil being sucked in to air stream
c) helps to keep the shaft cool by controlled leakage of air
d) none of the above
Answer-May be D but Not Sure(Because Labyrinth seals or glands are fitted to the shaft and casing to prevent the leakage of exhaust gas into the turbine end bearing, or to prevent oil being drawn into the compressor. To assist in the sealing effect, air from the compressor volute casing is led into a space within the gland. A vent to atmosphere at the end of the labyrinth gives a guide to the efficiency of the turbine end gland. Discoloring of the oil on a rotor fitted with a roller bearing will also indicate a failure in the turbine end gland)
Q- In the _____ type of t/c 2/s diesel engine is _____ to start.