1|Page
Boiler Exam Practice Tests (NEW UPDATED VERSION) LATEST
ACTUAL EXAM QUESTIONS AND CORRECT ANSWERS (VERIFIED
QUESTIONS AND ANSWERS)- GUARANTEED PASS A+ UPDATED
BOILER EXAM PRACTICE TEST – A2
Fluid Mechanics & Heat Transfer
(LATEST UPDATED – 2026 STANDARD)
1.
Which property of a fluid primarily resists flow?
A. Density
B. Viscosity
C. Specific volume
D. Compressibility
Answer: B
Rationale: Viscosity represents internal resistance to fluid motion and directly affects
friction losses.
2.
Laminar flow in a pipe typically occurs when Reynolds number is:
A. Above 10,000
B. Between 4,000–10,000
C. Below 2,000
D. Independent of velocity
Answer: C
Rationale: Laminar flow exists at Reynolds numbers less than approximately 2,000.
2026 2027 GRADED A+
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3.
What happens to pressure losses if pipe diameter is reduced?
A. Decrease
B. Remain constant
C. Increase
D. Become zero
Answer: C
Rationale: Smaller diameters increase velocity and friction, raising pressure losses.
4.
Which equation is used to calculate friction head loss in pipes?
A. Bernoulli
B. Fourier
C. Darcy–Weisbach
D. Boyle’s Law
Answer: C
Rationale: Darcy–Weisbach equation determines frictional head loss in fluid flow.
5.
Which type of heat transfer dominates in boiler furnaces?
A. Conduction
B. Convection
C. Radiation
D. Evaporation
Answer: C
Rationale: Radiation is dominant at high furnace temperatures.
6.
What increases convective heat transfer coefficient?
2026 2027 GRADED A+
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A. Lower velocity
B. Higher viscosity
C. Higher fluid velocity
D. Lower temperature difference
Answer: C
Rationale: Increased velocity improves turbulence and heat transfer.
7.
Which fluid property affects Reynolds number the most?
A. Temperature
B. Density
C. Viscosity
D. Pressure
Answer: C
Rationale: Viscosity strongly influences flow regime classification.
8.
In forced convection, heat transfer depends mainly on:
A. Gravity
B. Fluid velocity
C. Radiation
D. Phase change
Answer: B
Rationale: Forced convection relies on externally driven fluid motion.
9.
Which heat exchanger arrangement is most efficient?
A. Parallel flow
B. Counterflow
C. Crossflow
D. Single pass
2026 2027 GRADED A+
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Answer: B
Rationale: Counterflow maintains higher temperature gradients across the exchanger.
10.
Which fouling effect reduces boiler efficiency?
A. Higher emissivity
B. Increased heat transfer
C. Insulation on tubes
D. Clean surfaces
Answer: C
Rationale: Fouling acts as insulation, reducing heat transfer efficiency.
11.
What does Nusselt number represent?
A. Pressure loss
B. Heat transfer enhancement
C. Fluid velocity
D. Temperature difference
Answer: B
Rationale: Nusselt number relates convective to conductive heat transfer.
12.
Which flow meter measures pressure differential?
A. Rotameter
B. Orifice plate
C. Turbine meter
D. Magnetic meter
Answer: B
Rationale: Orifice plates create a pressure drop proportional to flow rate.
2026 2027 GRADED A+
Boiler Exam Practice Tests (NEW UPDATED VERSION) LATEST
ACTUAL EXAM QUESTIONS AND CORRECT ANSWERS (VERIFIED
QUESTIONS AND ANSWERS)- GUARANTEED PASS A+ UPDATED
BOILER EXAM PRACTICE TEST – A2
Fluid Mechanics & Heat Transfer
(LATEST UPDATED – 2026 STANDARD)
1.
Which property of a fluid primarily resists flow?
A. Density
B. Viscosity
C. Specific volume
D. Compressibility
Answer: B
Rationale: Viscosity represents internal resistance to fluid motion and directly affects
friction losses.
2.
Laminar flow in a pipe typically occurs when Reynolds number is:
A. Above 10,000
B. Between 4,000–10,000
C. Below 2,000
D. Independent of velocity
Answer: C
Rationale: Laminar flow exists at Reynolds numbers less than approximately 2,000.
2026 2027 GRADED A+
,2|Page
3.
What happens to pressure losses if pipe diameter is reduced?
A. Decrease
B. Remain constant
C. Increase
D. Become zero
Answer: C
Rationale: Smaller diameters increase velocity and friction, raising pressure losses.
4.
Which equation is used to calculate friction head loss in pipes?
A. Bernoulli
B. Fourier
C. Darcy–Weisbach
D. Boyle’s Law
Answer: C
Rationale: Darcy–Weisbach equation determines frictional head loss in fluid flow.
5.
Which type of heat transfer dominates in boiler furnaces?
A. Conduction
B. Convection
C. Radiation
D. Evaporation
Answer: C
Rationale: Radiation is dominant at high furnace temperatures.
6.
What increases convective heat transfer coefficient?
2026 2027 GRADED A+
,3|Page
A. Lower velocity
B. Higher viscosity
C. Higher fluid velocity
D. Lower temperature difference
Answer: C
Rationale: Increased velocity improves turbulence and heat transfer.
7.
Which fluid property affects Reynolds number the most?
A. Temperature
B. Density
C. Viscosity
D. Pressure
Answer: C
Rationale: Viscosity strongly influences flow regime classification.
8.
In forced convection, heat transfer depends mainly on:
A. Gravity
B. Fluid velocity
C. Radiation
D. Phase change
Answer: B
Rationale: Forced convection relies on externally driven fluid motion.
9.
Which heat exchanger arrangement is most efficient?
A. Parallel flow
B. Counterflow
C. Crossflow
D. Single pass
2026 2027 GRADED A+
, 4|Page
Answer: B
Rationale: Counterflow maintains higher temperature gradients across the exchanger.
10.
Which fouling effect reduces boiler efficiency?
A. Higher emissivity
B. Increased heat transfer
C. Insulation on tubes
D. Clean surfaces
Answer: C
Rationale: Fouling acts as insulation, reducing heat transfer efficiency.
11.
What does Nusselt number represent?
A. Pressure loss
B. Heat transfer enhancement
C. Fluid velocity
D. Temperature difference
Answer: B
Rationale: Nusselt number relates convective to conductive heat transfer.
12.
Which flow meter measures pressure differential?
A. Rotameter
B. Orifice plate
C. Turbine meter
D. Magnetic meter
Answer: B
Rationale: Orifice plates create a pressure drop proportional to flow rate.
2026 2027 GRADED A+
