Comp 6 Flashcards
1
Q
- Compared to 4-stroke/cycle engines, 2-stroke/cycle diesel engines have the disadvantage of:
A. Greater weight/size requirements
B. Fewer power strokes per volume
C. Higher cylinder head temperatures
D. Less even torque
A
C. Higher cylinder head temperatures
2
Q
- The low pressure side of refrigeration system is considered to exist from the ______.
A. Receiver to the expansion coil.
B. Condenser to the expansion valve.
C. Expansion valve to the compressor.
D. Expnsion valve to the evaporator.
A
C. Expansion valve to the compressor.
3
Q
- The pump packing gland has been repeatedly tightened by small increments until the gland has bottomed. Which of the actions listed should be carried out next if the leakage continues to be excessive?
A. Continue to add more turns of packing.
B. Replace with larger cross sectional turne of packing.
C. Replace all of the packing.
D. Replace the soft packing with packing turns that are covered with lead wrap.
A
A. Continue to add more turns of packing
4
Q
- On a 4-cycle diesel engine, the valve subjected to the most severe conditions during normal service is the:
A. Air starting valve
B. Cylinder relief valve
C. Cylinder exhaust valve
D. Air inlet valve
A
C. Cylinder exhaust valve
5
Q
- A diesel engine is supercharged in order to:
A. Provide more fuel for combining the air
B. Provide more air for combining with the fuel
C. Increased the no-load RPMs
D. Lower the no-load RPMs
A
B. Provide more air for combining with the fuel
6
Q
- What would you do when securing a flash type evaporator for an extended period of time?
A. Tightly seal the unit to exclude air.
B. Completely drain the unit.
C. Fill the unit with descaling compound.
D. Fill the unit with saltwater.
A
B. Completely drain the unit.
7
Q
- The pupose of separating the nozzle in the accumulator of water tube, coil type, steam generator is to separate _____.
A. Dry steam from the steam and water mixture.
B. Condensate from feed water.
C. Superheated steam from saturated steam.
D. Sludge accumulation from feed water.
A
A. Dry steam from the steam and water mixture.
8
Q
- The process if scavenging a 2-stroke / cycle diesel engine serves to.
A. Reduce the intake air charge density.
B. Cool the exhaust valves.
C. Thermal efficiency
D. Increase the temperature of exhaust gases.
A
B. Cool the exhaust valves.
9
Q
- If a 4-stroke/cycle diesel engine is running at 1550 RPM, the speed if the camshaft will be:
A. 775 RPM
B. 1550 RPM
C. 525 RPM
D. 1800 RPM
A
A. 775 RPM
10
Q
- A squealing sound generated by a reciprocating air compressor upon starting may include:
A. Defective unloader
B. Badly leaking valves
C. Abnormally tight drive belts
D. Compressor interstage leakage
A
A. Defective unloader
11
Q
- In a gas turbine plant installed with a heat exchanger, the compressed air receives heat from the exhaust gases before it reaches the combustion chamber, which results to the quantity of fuel used, being reduced and therefore, an improvement of thermal efficiency. Why is this reduction of fuel happening?
A. Because the density of compressed air is reduced.
B. Because the density of compressed air is increased.
C. Because the temparature rise required in the combustion chamber increased.
D. Because the temparature rise required in the combustion chamber is reduced.
A
D. Because the temparature rise required in the combustion chamber is reduced.
12
Q
- What us the purpose of propeller fairwater cone during the engine is in operation?
A. Lock the propeller nut in position.
B. Eliminate axial thrust.
C. Eliminate cavitation.
D. Minimize water turbulence.
A
D. Minimize water turbulence.
