Update | Graded A+
1. Which exhaust gas /gasses are controlled by the EGR valve?
CO and HC
HC
NOx
CO, HC, and NOx
2. What is the term for the process in which calcium carbonate decomposes in a
boiler to release carbon dioxide?
Evaporation
Hydration
Condensation
Calcination
3. What is the advantage of an open feed water heater compared to a closed
feed water heater?
A closed feed water heater is suitable for heating hard water
An open system feed water heater removes more oxygen more
rapidly than a closed system
In a closed feed water system, the steam and water come in direct
contact with each other
An open feed water heater heats the condensate by the following
design: outside of the tubes contains feed water and inside of the
tubes contains the steam
,4. What is the effect of bypassing air around the air heater when the boiler
steam load is at a minimum?
The fuel consumption decreases.
The water temperature rises.
The efficiency of the boiler decreases.
The steam pressure increases.
5. Rapid oxidation that produces instant heat and light is called:
Endothermic
Ionization
Hypothermic
Combustion
6. The operator of a compression refrigeration system containing R-134a orders
one hundred pounds of refrigerant to charge the machine. The color of the
cylinders that the refrigerant comes in is most nearly:
Sky or light blue
Orange
Deep green
Tan
7. Describe the significance of the power capacity rating in transformers and
how it affects their application.
The power capacity rating determines the voltage level at which the
transformer operates.
, The power capacity rating indicates the maximum load a
transformer can handle without overheating, which is crucial for
ensuring safe and efficient operation.
The power capacity rating is irrelevant to the transformer’s efficiency.
The power capacity rating only affects the physical size of the
transformer.
8. What is the typical range indicated on a boiler steam pressure gauge?
0 to 30 psi
0 to 100 psi
0 to 50 psi
0 to 15 psi
9. A dryback scotch marine firetube boiler is 8′-6″ in diameter and has a flue
furnace that is 30″ in diameter. The boiler is 17′-3″ long and has 122 tubes that
are 2″ in diameter. If the tube sheets are disregarded, the boiler has ___ sq ft of
heating surface.
188
1699
1063
1239
10. What is the primary purpose of a three-element regulator in boiler systems?
To regulate fuel flow to the burner.
To maintain the water level in the boiler.
To monitor pressure levels in the system.
, To control the temperature of the steam.
11. Describe how stack temperature and furnace pressure can affect the thermal
efficiency of a boiler.
Lower stack temperatures always improve thermal efficiency.
Both stack temperature and furnace pressure are irrelevant to thermal
efficiency.
Higher stack temperatures can indicate energy loss, while optimal
furnace pressure can enhance combustion efficiency.
Stack temperature has no effect on thermal efficiency, but furnace
pressure is critical.
12. What is the primary method used to remove non-condensables from a
condenser?
By using a vacuum pump
By increasing the temperature
By using a filter
By adding water
13. The primary winding of a transformer is a coil that
Receives the energy from the supply
Transfers, the energy
Changes electrical energy into mechanical energy
Changes magnetic energy into electrical energy
14. Modern combustion turbines used for electric generation utilize which
technology to provide the most