125) The possibility of damage from operating a diesel engine at critical speeds is reduced by the use of
a)an isochronous governor
b)elastic engine mounts
c)a vibration damper
d)a cast iron bed plate with good flexible qualities
126). In a diesel engine lube oil system, which of the following parts should be lubricated first?
127) When fuel oil heaters are required for engine operation,
)each heater shall have the capacity to supply the main engine at full power
b)at least two heaters of approximately equal size are to be installed
c)the system shall be designed to permit series or parallel operation
d)none of the above
128) An advantage of aluminium pistons compared to cast iron pistons is:
a)greater high temperature strength
b)better heat conductivity
c)greater weight per cubic cm
d)increased resistance to wear
129) Which engine component increases air density and helps to improve engine operating efficiency?
130) An electric heater built into the cylinder water jacket would be used to
a)raise lube oil viscosity for easier starting in cold weather
b)increase air inlet temperature
c)increase compression ratio
d)increase water temperature for easier starting in cold weather
131) Which is found with both mechanical and hydraulic governors?
a)direct linkage between the ball head and fuel rack
c)a compensating device
132) Which of the following design features will reduce the possibility of overheating the top compression rings of a cast iron piston?
a)The top ring is located as close to the piston as possible
b)The inside surface of the piston head is rounded into the ring belt
c)A nickel-bearing insert is cast into the top ring groove
d)A heat dam design is sometimes used in the piston head
Answer-DNEXT Prepare for MMD Class 4 Objective