3e151 B Set Vol 2

100 Questions | Total Attempts: 761

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CDCs Quizzes & Trivia

UREs for B set of 3E151 cdcs Vol 2.


Questions and Answers
  • 1. 
    The inside part of the a heat exchanger in a forced-warm air furnace is known as the
    • A. 

      Burner cone

    • B. 

      Draft chamber

    • C. 

      Casing chamber

    • D. 

      Combustion chamber

  • 2. 
    Three common types of bearing used on warm-air furnace assemblies
    • A. 

      Anti-friction, sleeve, and bronze

    • B. 

      Sleeve, thrust, and anti-friction

    • C. 

      Plain, thrust, and anti-friction

    • D. 

      Thrust, plain, and bronze

  • 3. 
    What type of warm-air furnace is known as a high-boy furnace?
    • A. 

      Horizontal

    • B. 

      Downflow

    • C. 

      Gravity

    • D. 

      Upflow

  • 4. 
    Gas burners primary controls operate in response to signals received from
    • A. 

      Relays

    • B. 

      Switches

    • C. 

      Thermostats

    • D. 

      A heating element

  • 5. 
    When the tempetature in a gas-fired furnance becomes excessive, what unit stops the burner?
    • A. 

      Delayed-action control

    • B. 

      Starting control

    • C. 

      Ignition control

    • D. 

      Limit control

  • 6. 
    The delayed-action control is a primary control that is usually used with 
    • A. 

      A stoker

    • B. 

      An oil burner

    • C. 

      A gas burner

    • D. 

      A coal hand-fired furnace

  • 7. 
    The most important inspection you perform on a gas-fired furnace is one for 
    • A. 

      Power

    • B. 

      Unit size

    • C. 

      A gas leak

    • D. 

      Unit location

  • 8. 
    What is the most serious defect to look for when you inspet a heat exchanger?
    • A. 

      Warped metal

    • B. 

      Soot deposits

    • C. 

      Blockages

    • D. 

      Cracks

  • 9. 
    When you perform a test to ensure that the safety limit control is operating properly, which circuit do you disconnect?
    • A. 

      Blower

    • B. 

      Burner

    • C. 

      Pilot

    • D. 

      Main

  • 10. 
    What type of gas space heaters can be gravity or mechanical air-circulation type and vented or unvented type?
    • A. 

      Ceiling

    • B. 

      Floor

    • C. 

      Room

    • D. 

      Wall

  • 11. 
    Which space heater must be used inly in a well-ventilated rooms?
    • A. 

      Wall

    • B. 

      Room

    • C. 

      Vented

    • D. 

      Unvented

  • 12. 
    What is the maximum Btu input for an unvented space heater?
    • A. 

      50,000 btu/h

    • B. 

      40,000 btu/h

    • C. 

      30,000 btu/h

    • D. 

      20,000 btu/h

  • 13. 
    Which type of space heater control valve has an infinite number of fuel firing rates between high fire and low fire?
    • A. 

      Step-modulating

    • B. 

      Single-stage

    • C. 

      Two-stage

    • D. 

      Manual

  • 14. 
    Whose instructions must you follow when you inspect gas-fired heaters?
    • A. 

      Air force bulletins

    • B. 

      Air force procedures

    • C. 

      Manufacturers' instructions

    • D. 

      Local procedures and air force bulletins

  • 15. 
    What method of heat transfer is used when floors or other objects reradiate to the air?
    • A. 

      Conduction

    • B. 

      Convection

    • C. 

      Radiation

    • D. 

      Absorption

  • 16. 
    Infrared heaters are not used in an area that contains ignitable dust, gases, or vapors in hazardous concentrations because of
    • A. 

      Their very low surface temperature

    • B. 

      Their high surface temperature

    • C. 

      The porosity of their ceramic elements

    • D. 

      The possibility of corrosion damage to the elements

  • 17. 
    The fan control has two settings; the fan OFF temperature is generally set at
    • A. 

      20 to 25*F above the desired room temperature

    • B. 

      15 to 20*F above the desired room temperature

    • C. 

      10 to 15*F above the desired room temperature

    • D. 

      5 to 10*F above the desired room temperature

  • 18. 
    While troubleshooting a warm-air heating system, you notice the flame burning in a long, yellow-tipped manner?  What would cause this to happen?
    • A. 

      A strong updraft

    • B. 

      A very weak cross draft

    • C. 

      Low voltage in the control circuit

    • D. 

      Insufficient primary combustion

  • 19. 
    When troubleshooting a gas-fired warm-air furnace, the unit is functioning eletrically but does not operate. What could be the cause of the type malfunction?
    • A. 

      An open gas valve

    • B. 

      A closed gas valve

    • C. 

      An open alarm circuit

    • D. 

      A closed thermostat circuit

  • 20. 
    What surrounds the tubes of water-tube boiler?
    • A. 

      Hot gases

    • B. 

      Hot air

    • C. 

      Water

    • D. 

      Steam

  • 21. 
    An increase in pressure and the surface of water will
    • A. 

      Increase the boiling point

    • B. 

      Decrease the boiling point

    • C. 

      Increase the molecular count

    • D. 

      Decrease the molecular count

  • 22. 
    The formula for determining the temperature of water at a given steam pressure is
    • A. 

      Square root of the psi + 14 x 198

    • B. 

      Square root of the psi x 14 + 198

    • C. 

      198 X 14 + square root of the psi

    • D. 

      198 + 14 x the square root of the psi

  • 23. 
    The internal feedline is installed in the water space near, but not touching, the
    • A. 

      Downcomer tubes

    • B. 

      Side of the drum

    • C. 

      Bottom of the drum

    • D. 

      Surface blowdown line

  • 24. 
    Flat surfaces of a boiler are held in place by braces, which are called
    • A. 

      Baffles

    • B. 

      Tubes

    • C. 

      Stays

    • D. 

      Drums

  • 25. 
    Water hammer in a piping sysytem is prevented by using
    • A. 

      Open traps

    • B. 

      Flash tanks

    • C. 

      Saturated pressure

    • D. 

      Pressure release valves

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