Ac333 Practice Questions
AC333 Practice Questions
- 1.
The resistance wire often used in an electric heating element is made of:
- A.
Copper.
- B.
Stainless steel.
- C.
Nickel chromium.
- D.
Magnesium
Correct Answer
C. Nickel chromium. -
- 2.
Radiant heat is transferred by:
- A.
Ultraviolet rays.
- B.
Infrared rays.
- C.
Ionization.
- D.
Diffraction
Correct Answer
B. Infrared rays. -
- 3.
Most electric baseboards units are _________
- A.
Natural-draft convection
- B.
Forced-draft convection
- C.
Forced-draft conduction
- D.
Radiant
Correct Answer
A. Natural-draft convection -
- 4.
Central forced-air electric furnaces frequently use _________ to start and stop multiple heating circuits.
- A.
Capacitors
- B.
Sequencers
- C.
Limit controls
- D.
Cool anticipators
Correct Answer
B. Sequencers -
- 5.
A sequencer utilizes a _________ to initiate its operation.
- A.
Bimetal heat motor
- B.
Bimetal snap disc
- C.
Capacitor
- D.
Nichrome resistor
Correct Answer
A. Bimetal heat motor -
- 6.
The component located in the thermostat that shuts the electric furnace down prematurely so that the space will not be overheated is the:
- A.
Sequencer.
- B.
Cool anticipator.
- C.
Heat anticipator.
- D.
Mercury bulb.
Correct Answer
C. Heat anticipator. -
- 7.
The disadvantage in using a contactor to open and close the circuit to the electric heating elements is the:
- A.
Noise it makes.
- B.
Low-control voltage.
- C.
Heating elements would all be started at the same time unless separate time delay relays were used.
- D.
Both A and C.
Correct Answer
D. Both A and C. -
- 8.
A limit switch or control is used to:
- A.
Start the furnace if the thermostat malfunctions.
- B.
Ensure that the fan stops when the furnace cools down.
- C.
Starts the furnace prematurely on a cold day.
- D.
Open the circuit to the heating elements if the furnace overheats.
Correct Answer
D. Open the circuit to the heating elements if the furnace overheats. -
- 9.
Electric unit heaters are usually installed:
- A.
Hanging from the ceiling.
- B.
As baseboard heat.
- C.
As forced-air furnaces.
- D.
For hot water systems.
Correct Answer
A. Hanging from the ceiling. -
- 10.
Electric ceiling panel heat:
- A.
Easily adapts to central air conditioning.
- B.
Is radiant-type heat.
- C.
Uses circulating hot water.
- D.
Can easily have humidity equipment added to the system.
Correct Answer
B. Is radiant-type heat. -
- 11.
The _____________ thermostat is commonly used for forced-air electric furnace installations.
- A.
Low-voltage
- B.
All-voltage
- C.
No-voltage
- D.
High-voltage
Correct Answer
A. Low-voltage -
- 12.
The _____________ thermostat is commonly used for baseboard electric heat installations.
- A.
Low-voltage
- B.
All-voltage
- C.
No-voltage
- D.
High-voltage
Correct Answer
D. High-voltage -
- 13.
The control voltage for the controls on a sequencer are typically:
- A.
24 V.
- B.
208 V.
- C.
460 V.
- D.
12 V.
Correct Answer
A. 24 V. -
- 14.
An electric furnace is operating on 225 V and is drawing 83 amps. What heat capacity is this furnace putting out?
- A.
55,787 Btu/h
- B.
33,467 Btu/h
- C.
98,953 Btu/h
- D.
63,738 Btu/h
Correct Answer
D. 63,738 Btu/hExplanation
225 x 83 x 3.413 = 63,738Rate this question:
-
- 15.
Radon is a(an):
- A.
Radioactive gas.
- B.
Refrigerant used for special systems.
- C.
Oil additive.
- D.
Filter media.
Correct Answer
A. Radioactive gas. -
- 16.
Formaldehyde byproducts may be found in:
- A.
Old fruits and vegetables.
- B.
Aerosols.
- C.
Cleaning supplies.
- D.
Pressboard and carpets.
Correct Answer
D. Pressboard and carpets. -
- 17.
Dust mites are:
- A.
Usually found in damp areas in basements.
- B.
Often found in dust blown through vacuums with HEPA filters.
- C.
Microscopic spider-like insects.
- D.
Related to mold spores.
Correct Answer
C. Microscopic spider-like insects. -
- 18.
Mold:
- A.
Is usually found in dusty, dry areas.
- B.
Is usually found in areas where there is moisture and/or high humidity.
- C.
Is seldom found in areas where it can be seen.
- D.
Spores are not harmful to humans.
Correct Answer
B. Is usually found in areas where there is moisture and/or high humidity. -
- 19.
The first step with regard to mold cleanup should be:
- A.
Remove the source of moisture.
- B.
Vacuum the area.
- C.
Check for radioactive activity.
- D.
Check the filter media in the area.
Correct Answer
A. Remove the source of moisture. -
- 20.
Carbon monoxide:
- A.
Has a bluish color.
- B.
Can easily be seen.
- C.
Is heavier than air.
- D.
Is produced by incomplete combustion in appliances that use the combustion process.
Correct Answer
D. Is produced by incomplete combustion in appliances that use the combustion process. -
- 21.
Auto exhaust produces carbon monoxide.
- A.
True
- B.
False
Correct Answer
A. True -
- 22.
Wood smoke may contain:
- A.
Polycyclic organic matter.
- B.
Nonpolycyclic organic matter.
- C.
Particles from combustion.
- D.
All of the above.
Correct Answer
D. All of the above. -
- 23.
Disturbed materials containing asbestos:
- A.
Should be brushed down and swept up by the HVAC technician.
- B.
Should be removed by a certified or licensed contractor.
- C.
May be removed when found as part of a mold remediation program.
- D.
Should be vacuumed up when found.
Correct Answer
B. Should be removed by a certified or licensed contractor. -
- 24.
Ventilation is:
- A.
A problem to deal with.
- B.
Generally not recommended.
- C.
Never used in a residence.
- D.
The process of supplying or removing air by natural or mechanical means.
Correct Answer
D. The process of supplying or removing air by natural or mechanical means. -
- 25.
Duct cleaning is accomplished by:
- A.
Polishing the outside of the duct.
- B.
Washing out with with a hose and water.
- C.
Using compressed air.
- D.
Using a vacuum system and brushing.
Correct Answer
D. Using a vacuum system and brushing. -
- 26.
All humidifiers must:
- A.
Be installed correctly.
- B.
Be serviced regularly.
- C.
Use good water.
- D.
All of the above.
Correct Answer
D. All of the above. -
- 27.
Air in homes tend to be drier in the:
- A.
Summer.
- B.
Winter.
Correct Answer
B. Winter. -
- 28.
If the relative humidity is 60%, it means that:
- A.
40% of air is moisture.
- B.
60% of the air is moisture.
- C.
The air has 60% of the moisture it has the capacity to hold.
- D.
The air has 40% of the moisture it has the capacity to hold.
Correct Answer
C. The air has 60% of the moisture it has the capacity to hold. -
- 29.
Humidification generally relates to a process of causing water to ________ into the air:
- A.
Condense
- B.
Evaporate
- C.
Be ionized
- D.
Be filtered
Correct Answer
B. Evaporate -
- 30.
Infrared humidifiers reflect infrared energy:
- A.
Into the air.
- B.
Onto water.
- C.
Onto an evaporative media.
- D.
Into a hydronic boiler.
Correct Answer
B. Onto water. -
- 31.
A humidistat has ________ element and is generally used to control a humidifier.
- A.
A moisture-sensitive
- B.
A light-sensitive
- C.
An infrared-sensing
- D.
An air pressure-sensing
Correct Answer
A. A moisture-sensitive -
- 32.
Atomizing humidifiers discharge ________ into the air.
- A.
Water vapor
- B.
Electronic ions
- C.
Trivalent oxygen
- D.
Tiny water droplets
Correct Answer
D. Tiny water droplets -
- 33.
Two types of atomizing humidifiers are the:
- A.
Thermistor and ionization generator.
- B.
Spray nozzle and centrifugal.
- C.
Disc and drum types.
- D.
Particulate and oxidation types.
Correct Answer
B. Spray nozzle and centrifugal. -
- 34.
If reservoir-type humidifiers are not properly maintained, which of the following may collect and be discharged into the air?
- A.
Fungi
- B.
Bacteria
- C.
Algae
- D.
All of the above
Correct Answer
D. All of the above -
- 35.
In the ionizing section of an electronic air cleaner, the particles in the air are:
- A.
Trapped by a filter.
- B.
Charged with an electrical charge.
- C.
Washed with a special cleaner.
- D.
Treated to remove many of the odors.
Correct Answer
B. Charged with an electrical charge. -
- 36.
Extended surface filters often use ________, which provides air cleaning efficiencies up to three times greater than those of fiberglass.
- A.
Trivalent oxygen
- B.
Charcoal
- C.
Stainless steel
- D.
Nonwoven cotton
Correct Answer
D. Nonwoven cotton -
- 37.
Typically, air-conditioning (cooling) systems require an airflow of ________ cfm per ton.
- A.
200
- B.
400
- C.
600
- D.
800
Correct Answer
B. 400 -
- 38.
If air conditioning is added to a heating system, the supply duct should be insulated to keep it from sweating and to keep the air in the duct from ________ in the cooling season.
- A.
Absorbing heat
- B.
Giving up heat
- C.
Becoming too dry
Correct Answer
A. Absorbing heat -
- 39.
A heating system typically requires ________ a cooling system.
- A.
Less airflow than
- B.
Greater airflow than
- C.
About the same airflow as
Correct Answer
A. Less airflow than -
- 40.
In evaluating an air distribution system, the terminal units called the ________ are an important factor.
- A.
Electric baseboard heaters and radiators
- B.
Evaporator and condenser
- C.
Grilles and registers
- D.
Blower and damper
Correct Answer
C. Grilles and registers -
- 41.
When two low-voltage transformers are wired in parallel, care must be taken to ensure that they are wired:
- A.
In phase.
- B.
In a circuit with the same resistance
- C.
So that they produce the same amperage.
Correct Answer
A. In phase. -
- 42.
When adding an air-conditioning system to an existing furnace, frequently a ________ must be added to the control circuits.
- A.
Thermocouple and limit switch
- B.
Glow coil and static pressure disc
- C.
Transformer and fan relay
- D.
Stack switch and cad cell
Correct Answer
C. Transformer and fan relay -
- 43.
When designing an all-weather system, the ductwork is designed around ________ system.
- A.
The cooling
- B.
The heating
- C.
Either the heating or cooling
Correct Answer
A. The cooling -
- 44.
Too much airflow across the heat exchanger in a gas or oil heating system can cause ________ problems.
- A.
Venting
- B.
Poor combustion
- C.
Intermittent ignition
- D.
Flame retention
Correct Answer
A. Venting -
- 45.
When adding a control transformer for air conditioning to an existing heating system, the second transformer can be wired in parallel with the original or:
- A.
In a series with the original.
- B.
As a separate circuit.
- C.
In a parallel with the fan relay.
- D.
In a parallel with the compressor contactor.
Correct Answer
B. As a separate circuit. -
- 46.
You need to install a 3-ton air-conditioning system on an existing furnace. Using the chart in the text, Figure 42-4, which of the following will meet the fan needs?
- A.
¼ HP and a fan wheel that is 10" in diameter and 8" wide.
- B.
⅓ HP and a fan wheel that is 10" in diameter and 8" wide.
- C.
⅓ HP and a fan wheel that is 9" in diameter and 9" wide.
- D.
¼ HP and a fan wheel that is 9" in diameter and 8" wide.
Correct Answer
B. ⅓ HP and a fan wheel that is 10" in diameter and 8" wide. -
- 47.
A 2½-ton cooling system must circulate approximately __________ cfm of air.
- A.
800
- B.
1000
- C.
1400
- D.
2000
Correct Answer
B. 1000 -
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Jul 30, 2011Quiz Edited by
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Jan 18, 2010Quiz Created by
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