Power Engineering - 4B7 Practice Questions With Complete
Solutions
_______________ causes the fuel to ignite in a diesel engine.
a. A precisely timed glow plug.
b. The pressure of the injected fuel.
c. The high temperature compressed air in the engine cylinder.
d. The fuel injector nozzle. Correct Answers c. The high
temperature compressed air in the engine cylinder.
4B07-03-05-03 To prevent cooling tower basin water from
freezing during cold weather, many units:
a. have automatic ethylene glycol antifreeze injection systems.
b. have thermostatically controlled electric basin heaters.
c. have automatic gas-fired sump heaters .
d. use salt brine instead of water. Correct Answers b. have
thermostatically controlled electric basin heaters.
4B07-04-01-02 The combustion chamber of a gas turbine:
a. increases the density of the compressed air.
b. must be water cooled to protect against high temperature.
c. is where fuel is added to air, and burned.
d. preheats the combustion air before it is compressed. Correct
Answers c. is where fuel is added to air, and burned.
4B07-04-01-03 A two shaft gas turbine:
a. has the load turbine downstream from the compressor turbine
,b. is always an open cycle
c. uses two shafts, geared together
d. is always regenerative Correct Answers a. has the load
turbine downstream from the compressor turbine
4B07-04-01-04 The output power of a gas turbine depends upon
a. the mass of hot gas passing through the turbine per unit time
b. the temperature at the turbine inlet in Kelvin
c. the drive gear ratio between the turbine and compressor
d. the difference between inlet air and turbine exhaust
temperature Correct Answers a. the mass of hot gas passing
through the turbine per unit time
4B07-04-01-05 A closed cycle gas turbine:
a. Does not need a combustion chamber
b. Is the most common type of gas turbine
c. Recycles the same working fluid
d. Burns fuel with spent exhaust gas. Correct Answers c.
Recycles the same working fluid
4B07-04-01-06 A gas turbine is most efficient when:
a. both turbine shafts run at the same speed
b. the combustion chamber is kept cool
c. the ambient air temperature is low
d. operated at the highest combustion temperature that the
construction materials permit. Correct Answers d. operated at
the highest combustion temperature that the construction
materials permit.
, 4B07-04-01-07 A simple gas turbine is one without reheaters or:
a. Starting motors
b. Compressors
c. Combustors
d. Regenerators Correct Answers d. Regenerators
4B07-04-01-08 An essential auxiliary in a gas turbine
installation is:
a. an air heater
b. a generator
c. a water injection system
d. a starting motor Correct Answers d. a starting motor
4B07-04-02-01 Some of the characteristics that make the gas
turbine a better choice over other prime movers are:
a. its low power-to-weight ratio
b. its high thermal efficiency
c. its ability to rapidly start and carry full load
d. its low fuel consumption
e. Increased power output at higher elevations Correct Answers
c. its ability to rapidly start and carry full load
4B07-04-02-03 Gas turbines are ideal where:
a. noise is undesirable
b. water is scarce
c. thermal pollution is of major concern
Solutions
_______________ causes the fuel to ignite in a diesel engine.
a. A precisely timed glow plug.
b. The pressure of the injected fuel.
c. The high temperature compressed air in the engine cylinder.
d. The fuel injector nozzle. Correct Answers c. The high
temperature compressed air in the engine cylinder.
4B07-03-05-03 To prevent cooling tower basin water from
freezing during cold weather, many units:
a. have automatic ethylene glycol antifreeze injection systems.
b. have thermostatically controlled electric basin heaters.
c. have automatic gas-fired sump heaters .
d. use salt brine instead of water. Correct Answers b. have
thermostatically controlled electric basin heaters.
4B07-04-01-02 The combustion chamber of a gas turbine:
a. increases the density of the compressed air.
b. must be water cooled to protect against high temperature.
c. is where fuel is added to air, and burned.
d. preheats the combustion air before it is compressed. Correct
Answers c. is where fuel is added to air, and burned.
4B07-04-01-03 A two shaft gas turbine:
a. has the load turbine downstream from the compressor turbine
,b. is always an open cycle
c. uses two shafts, geared together
d. is always regenerative Correct Answers a. has the load
turbine downstream from the compressor turbine
4B07-04-01-04 The output power of a gas turbine depends upon
a. the mass of hot gas passing through the turbine per unit time
b. the temperature at the turbine inlet in Kelvin
c. the drive gear ratio between the turbine and compressor
d. the difference between inlet air and turbine exhaust
temperature Correct Answers a. the mass of hot gas passing
through the turbine per unit time
4B07-04-01-05 A closed cycle gas turbine:
a. Does not need a combustion chamber
b. Is the most common type of gas turbine
c. Recycles the same working fluid
d. Burns fuel with spent exhaust gas. Correct Answers c.
Recycles the same working fluid
4B07-04-01-06 A gas turbine is most efficient when:
a. both turbine shafts run at the same speed
b. the combustion chamber is kept cool
c. the ambient air temperature is low
d. operated at the highest combustion temperature that the
construction materials permit. Correct Answers d. operated at
the highest combustion temperature that the construction
materials permit.
, 4B07-04-01-07 A simple gas turbine is one without reheaters or:
a. Starting motors
b. Compressors
c. Combustors
d. Regenerators Correct Answers d. Regenerators
4B07-04-01-08 An essential auxiliary in a gas turbine
installation is:
a. an air heater
b. a generator
c. a water injection system
d. a starting motor Correct Answers d. a starting motor
4B07-04-02-01 Some of the characteristics that make the gas
turbine a better choice over other prime movers are:
a. its low power-to-weight ratio
b. its high thermal efficiency
c. its ability to rapidly start and carry full load
d. its low fuel consumption
e. Increased power output at higher elevations Correct Answers
c. its ability to rapidly start and carry full load
4B07-04-02-03 Gas turbines are ideal where:
a. noise is undesirable
b. water is scarce
c. thermal pollution is of major concern
