Exam Practice Questions And Correct

Power Plant Operator State Licensing Exam Practice Questions And Correct Answers (Verified Answers) Plus Rationales 2026 Q&A | Instant Download Pdf

1. In a steam power plant, the primary function of the boiler is to:

• Increase fuel efficiency
• Convert water into steam
• Condense exhaust steam
• Regulate turbine rotation

Rationale: The boiler’s key role is to generate steam by heating

water.

• The device used to remove dissolved oxygen from boiler feedwater is

called a:

• Economizer
• Deaerator 1 / 4

• Demineralizer
• Evaporator

Rationale: Deaerators remove dissolved gases like oxygen to prevent

corrosion.

3. A Bourdon gauge is used to measure:

• Temperature
• Pressure
• Flow rate
• Fuel quality

Rationale: Bourdon tubes convert pressure into mechanical motion

for measurement.

4. The main cause of scale formation in boilers is:

• High fuel pressure
• Excess lubrication
• Hard water impurities
• Low feedwater flow

Rationale: Minerals like calcium in hard water precipitate, forming

scale.

• What is the function of a steam turbine governor?
• Increase boiler steam output
• Reduce pump cavitation
• Regulate turbine speed
• Maintain water chemistry 2 / 4

Rationale: Governors maintain proper turbine RPM under load

variations.

6. Cavitation in pumps is primarily caused by:

• High oil viscosity
• High suction pressure
• Low suction pressure
• High discharge pressure

Rationale: Low suction pressure causes vapor bubbles that collapse

and damage pumps.

7. The pH of properly treated boiler water should be:

A) 2–3

B) 5–6

C) 10–11

D) 13–14

Rationale: Alkalinity prevents corrosion inside boilers.

8. A steam trap’s main purpose is to:

• Measure steam flow
• Remove condensate without losing live steam
• Lubricate turbine
• Separate solids

Rationale: Steam traps discharge condensate to maintain heat

efficiency. 3 / 4

• The law stating that pressure applied to a confined fluid is transmitted

equally is:

• Boyle’s Law
• Pascal’s Law
• Charles’s Law
• Dalton’s Law

Rationale: Pascal’s Law explains hydraulics and equal pressure

transmission.

10. The function of the economizer is to:

• Reduce steam pressure
• Store feedwater
• Recover heat from flue gases
• Increase boiler volume

Rationale: Economizers improve efficiency by preheating feedwater.

• A water-tube boiler has water where?
• Only in the drum
• Inside the tubes
• Inside the furnace walls
• Only in the economizer

Rationale: Water-tube boilers circulate water through tubes heated

externally.

• / 4