Heat Engines Questions With Complete Solutions
_______________ causes the fuel to ignite in a diesel engine.
Select one:
a. A precisely timed glow plug.
b. The fuel injector nozzle.
c. The high temperature compressed air in the engine cylinder.
d. The pressure of the injected fuel. Correct Answers C
A closed cycle gas turbine:
Select one:
a. Burns fuel with spent exhaust gas.
b. Recycles the same working fluid
c. Is the most common type of gas turbine
d. Does not need a combustion chamber Correct Answers B
A cold weather cooling tower bypass valve should not be fully
closed until the temperature reaches:
Select one:
a. about 27°C
b. +5°C
c. the point at which drift stops
d. the compressor setpoint Correct Answers A
A counter-flow cooling tower _____________ than a crossflow
cooling tower.
Select one:
a. requires less fan power
b. has a lower pressure drop
c. is shorter
,d. requires less floor space Correct Answers D
A gas turbine compressor:
Select one:
a. must be a multi-stage compressor
b. must be intercooled
c. can be driven by the load turbine
d. is always an axial compressor Correct Answers C
A gas turbine is most efficient when:
Select one:
a. operated at the highest combustion temperature that the
construction materials permit.
b. the ambient air temperature is low
c. the combustion chamber is kept cool
d. both turbine shafts run at the same speed Correct Answers A
A gas turbine must be rotated at _______ speed before ignition
begins.
Select one:
a. full
b. 20% to 30%of its maximum
c. 120%of its maximum
d. 10%of its maximum Correct Answers B
A gas turbine:
Select one:
a. Output increases when equipped with an air preheater
b. Operates the best when the inlet air is hot
c. Output increases when using air of maximum density
, d. Expands hot gases through the compressor Correct Answers
C
A heat engine is an operating cycle that uses a working fluid to
convert:
Select one:
a. Thermal energy to mechanical energy
b. Mechanical energy to electrical energy
c. Thermal energy to potential energy
d. Thermal energy to chemical energy Correct Answers A
A major difficulty encountered with a two-stroke cycle engine
is:
Select one:
a. The lack of torque at high speed
b. The difficulty in cold weather starting
c. The high speeds compared to an equivalent four-stroke engine
d. Exhausting the spent gases from the cylinder Correct Answers
D
A prime mover is
Select one:
a. the same as a "heat engine"
b. a device that uses a primary energy source to produce
mechanical work
c. a device used to remove air from pumping systems
d. a device that stores mechanical energy, such as a flywheel.
Correct Answers B
A reduction in sealing between the piston rings and the cylinder
wall may be the result of: