2027 Comprehensive Frequently Tested Questions
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100% Correct Detailed Answers
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1. The minimum flash point of #2 fuel oil is approximately:
A. 50°F
B. 75°F
C. 100°F
D. 150°F
Correct answer: C
2. The ignition point of #2 fuel oil is approximately:
A. 300°F
B. 400°F
C. 500°F
D. 700°F
Correct answer: C
3. What happens to fuel oil when it is heated?
A. Viscosity increases
B. Viscosity decreases
C. BTU content increases
,D. Density increases
Correct answer: B
4. The BTU content of #2 fuel oil is approximately:
A. 100,000 BTU/gal
B. 120,000 BTU/gal
C. 140,000 BTU/gal
D. 160,000 BTU/gal
Correct answer: C
5. On an adjustable head oil burner, the retention ring is mounted:
A. On the burner housing
B. Inside the combustion chamber
C. On the nozzle assembly
D. On the air tube only
Correct answer: C
6. Tertiary air is best defined as:
A. Air that cools the flame
B. Air that atomizes the oil
C. Air that ensures complete combustion
D. Air supplied after shutdown
Correct answer: C
7. Vaporizing oil burners are typically supplied with fuel by:
A. Pump pressure
B. Gravity flow
C. Compressed air
,D. Vacuum feed
Correct answer: B
8. The presence of soot in a vaporizing burner indicates:
A. Excess air
B. Proper operation
C. Too much oil
D. Insufficient draft
Correct answer: C
9. Flame retention oil burners typically produce flame temperatures in the range
of:
A. 1,000–1,500°F
B. 1,500–2,000°F
C. 2,000–3,000°F
D. 3,000–4,000°F
Correct answer: C
10. When fuel temperature decreases, the flow rate at the nozzle:
A. Decreases
B. Remains the same
C. Increases
D. Becomes unstable
Correct answer: C
11. Which instrument is used to measure electrical voltage?
A. Ammeter
B. Ohmmeter
, C. Voltmeter
D. Wattmeter
Correct answer: C
12. The minimum wire size required for a 20-amp circuit is:
A. #14 AWG
B. #12 AWG
C. #10 AWG
D. #8 AWG
Correct answer: B
13. The normal limit control circuit voltage in a heating system is:
A. 24 volts
B. 48 volts
C. 120 volts
D. 240 volts
Correct answer: C
14. Modern oil burners typically operate at a CO₂ level of:
A. 5–7%
B. 7–9%
C. 10–13%
D. 14–16%
Correct answer: C
15. Corrosion in a flue pipe occurs when:
A. Draft is too strong
B. Excess air is present