CDC 3E151B : Heating, Ventilation, And Refrigeration! Hardest Trivia Quiz

100 Questions  Settings  Have you just finished the CDC 3E151B course on Heating, Ventilation, And Refrigeration? What is a better way there to see how attentive you are than showing off how much you learned? Take up this quiz and review what you learned. Be sure to post your score to see how you fair among others. All the best of luck!

• 1.
Anything that has weight and takes up space is
• A.

Energy

• B.

Matter

• C.

Motion

• D.

Atoms

• 2.
What is the relationship among matter, energy, and heat?
• A.

Energy is made up of atoms, which consists of electrons kept in motion by matter, which is a form of heat

• B.

Heat is made up of molecules, which consists of electrons kept in motion by energy, which is a form of matter

• C.

Matter is made of atoms, which consists of electrons kept by heat, which is a form of energy

• D.

Energy is made up of molecules, which consists of electrons kept in motion by heat, which is a form of matter

• 3.
Conduction is the transfer of heat
• A.

Similar to that of light waves and radio waves

• B.

By the movement of a fluid such as air or water over a substance

• C.

Where a fan is used to propel the air across a hot or cold surface

• D.

Through a substance or from one body to another when the bodies are in direct contact

• 4.
What form of heat transfer most commonly used in the HVAC indusrty is
• A.

Conduction

• B.

Convection

• C.

• D.

• 5.
Sensible heat added to a substance will be indicated by a
• A.

Drop in temperature of that substance

• B.

Change in physical state of the substance

• C.

Stable temperature of that substance

• D.

Rise in temperature of that substance

• 6.
The heat that changes water at 212* F to steam at 212*F is known as
• A.

Latent heat of vaporization

• B.

Latent heat of condensation

• C.

Sensible heat of vaporization

• D.

Sensible heat of condensation

• 7.
Which is the correct formula for converting Fahrenheit to Celsius?
• A.

F = (C x 1.8) + 32

• B.

F = (C x 1.8) - 32

• C.

C = (F - 32) / 1.8

• D.

C = (F + 32) / 1.8

• 8.
What is the specific volume of one pound of dry air at standard conditions?
• A.

13.33 cubic feet

• B.

0.016 cubic feet

• C.

29.92 inches mercury

• D.

62.4 pounds/cubic foot

• 9.
To the closest tenth, what is normal atmospheric presure sea level?
• A.

11 psi

• B.

14.7 psi

• C.

110 psi

• D.

340 psi

• 10.
Where would you likely find the fasest moving air within a duct?
• A.

Along the walls

• B.

At the top

• C.

At the bottom

• D.

In the center

• 11.
Saturated steam is steam
• A.

With more heat added

• B.

At a temperature below boiling water

• C.

At a temperature above boiling water

• D.

At the temperature of boiling water

• 12.
To begin a plotting procedure on the psychometric chart, you must know the
• A.

Grains of moisture and specific heat

• B.

Dewpoint and wet-bulb temperatures

• C.

Wet-bulb and dry-bulb temperatures

• D.

Dry-bulb and dewpoint temperatures

• 13.
Heat content i plotted on the psychometric chart by extending the
• A.

Relative humidity line

• B.

Dew point line

• C.

Dry-bulb line

• D.

Wet-bulb line

• 14.
Refer to figure 1-10. If the wet-bulb temperature is 57*F and the dry-bulb temperature is 65*F, what is the relative humidity?
• A.

57 percent

• B.

61 percent

• C.

65 percent

• D.

70 percent

• 15.
Which process follows the line of constant enthalpy or has no heat change?
• A.

Latent heat process

• B.

Sensible heat process

• C.

Moisture injection process

• D.

• 16.
The term for temperature control that uses no external source of energy is
• A.

Pneumatic

• B.

Electronic

• C.

Self-contained

• D.

Electromechanical

• 17.
Hot-water reset is an example of what type of contol loop?
• A.

Open

• B.

Closed

• C.

Combination

• D.

Reverse reset

• 18.
What is a typical application of floating control?
• A.

Static pressure in a variable air volume system

• B.

Controlling temperature in a laboratory

• C.

Hot water reset from outdoor air

• D.

Room and discharge

• 19.
What mode of control corrects the problem of offset?
• A.

Proportional-plus-integral

• B.

Proportional-with-reset

• C.

Proportional

• D.

Floating

• 20.
Use the following information to answer this question about a pneumatic sensor: What is the output pressure of a pneumatic sensor with a range of 0* to 100* F if the temperature measured is 24*F?
• A.

3.52 psi

• B.

5.88 psi

• C.

9.20 psi

• D.

11.60 psi

• 21.
Use the following information to answer this question about a pneumatic sensor: What is the output pressure of a pneumatic sensor with a range of  50* to 100* F if the temperature measured is 80*F?
• A.

3.0 psi

• B.

8.6 psi

• C.

9.4 psi

• D.

10.2 psi

• 22.
Use the following information to answer this question about a single-input pneumatic controller: What is the proportional band required to obtain the desired performance?
• A.

5 percent

• B.

10 percent

• C.

15 percent

• D.

20 percent

• 23.
Use the following information to answer this question about a single-input pneumatic controller: What is the ouput of the contoller at 70*F?
• A.

3 psi

• B.

8 psi

• C.

10 psi

• D.

13 psi

• 24.
After you have drawn the performance graph for calibrating a single-input controller, what must you do next?
• A.

Find the transmitting pressure for both corners and the set point

• B.

Use a simulator in place of both sensors

• C.

Set the proportional

• D.

Adjust the controller P cal

• 25.
What is the last step in the calibration of a single-input pneumatic controller?
• A.

Adjust the calibration screw to equal the predicted output pressure

• B.

Adjust the sensors to the predicted output pressures

• C.

Disconnect the sensor simulators

• D.

Readjust the the proportional band

• 26.
What is the main difference in calibration between a single-input controller with remote sensor and one with a built-in sensor?
• A.

The dials must all be set to the specified values

• B.

The temperature must be measured at the sensor

• C.

A temperature simulator cannot be used in calibration

• D.

You must allow extra time for the system to stabilize

• 27.
If you are calibrating a contoller with a built-in sensor and you have adjusted the controller calibration screw to equal Pcal, your next step is to adjust the
• A.

Set point dial up by one-half the TRc

• B.

Sensitivity slides

• C.

Calibration screw

• D.

Pressure span

• 28.
On a pneumatic dual-input receiver controller, one sensor measures the primary variable. What does the second sensor measure?
• A.

Desired variable

• B.

Reset variable

• C.

Set point

• D.

Offset

• 29.
When the primary variable set point of a pneumatic dual-input controller decreases as the reset variable increases, what is the reset?
• A.

Counter

• B.

Straight

• C.

Direct

• D.

Reverse

• 30.
When calibrating a dual-input pneumatic controller, you adjust sensors oneand two to the set point value. Your next step is to adjust the
• A.

Action

• B.

Proportional band

• C.

Percent authority

• D.

Output pressure to equal calibration pressure (Pcal)

• 31.
After you have adjusted the proportinal band and percent authority on a dual-input controller, your next step is to
• A.

Draw performance graph

• B.

Find the sensor pressures

• C.

Disconnect both sensors and connect the simulator

• D.

Measure the output pressure

• 32.
When the pressure to the control point adjustment port of a pneumatic controller increases,the setpoint
• A.

Stabilizes

• B.

Decreases

• C.

Increases

• D.

Stays the same

• 33.
What is the easiest way to calibrate a pneumatic controller with a control point adjustment port?
• A.

Allow the system time to stabilize; then calibrate

• B.

Disconnect the control point adjustment pressure and calibrate the controller

• C.

Adjust the control point adjustment to maximum pressure; then, use the dual-input calibration procedures

• D.

Return the control point adjustment port to the calibration pressure; then, use the single-input calibration procedures

• 34.
Use the following information to answer the question: Honeywell 908B Total change set point = 10*F Total change CPA pressure = 5 psi Span of sensor = 100*F (0* to 100*F) If you used the second port of a pneumatic dual-input controller as a control adjustment, what should the authority setting be to obtain the desired performance?
• A.

6 percent

• B.

12 percent

• C.

24 percent

• D.

48 persent

• 35.
How does a mimimum-poisition pneumatic adapter relay work?
• A.

It will not allow output pressure to fall below a preset value

• B.

It selects both the high and low signal

• C.

It changes the signal from direct-acting to reverse-acting

• D.

It will not allow the output pressure to go above a preset value

• 36.
What is one type of controlled device used in pneumatice system?
• A.

Actuator

• B.

Switching relay

• C.

Square root extractor

• D.

Minimum position switch

• 37.
What function does spring range have in a pneumatic system?
• A.

The pressure range over which a high/low selector operates

• B.

The pressure range over which a program switch operates

• C.

The pressure range over which a actuator operates

• D.

The pressure range of a controller's internal parameters

• 38.
Where isthe best place to mount the components of a pneumatic control system?
• A.

Close to the equipment it is controlling

• B.

On a steady base away from vibration

• C.

On the side of an air handler

• D.

Close to main air supply

• 39.
When you troubleshoot a pneumatic control system, the first component you check is the
• A.

Sensor

• B.

Controller

• C.

• D.

Controlled device

• 40.
What is the first step in cleaning up a contaminated pneumatic air supply?
• A.

Calibrate the instruments

• B.

Use a degreasing compound

• C.

Stop the contamination at the source

• D.

Retrofit the compressor air supply equipment

• 41.
What should you do after you remove the vapor degreasing compound from a pneumatic system?
• A.

Turn on the fans

• B.

Calibrate the controller

• C.

Change the filters in the controller

• D.

Flush the system with a clean air supply

• 42.
The two main types of switches used in electronic controls are
• A.

Double pole, double throw and double pole, single throw

• B.

Single pole, double throw and single pole, single throw

• C.

Snap acting and mercury switch

• D.

Thermostatic and mercury

• 43.
What is the advantage of timed, two-position control?
• A.

The final control elements moves to a position equal to the amount the controlled variable moved

• B.

The controller never catches up with the controlled condition

• C.

It greatly reduces the swings in the controlled variable

• D.

The thermal timer will cool

• 44.
A major problem of proprotional control is
• A.

Offset

• B.

Sensitivity

• C.

The throttling range

• D.

The position of the final element

• 45.
When special requirements are line voltage, two-position, and "fail-safe," the type of electrical control motor you should use to operate a damper isthe series
• A.

40

• B.

60

• C.

80

• D.

90

• 46.
The difference between a series 60 and a series 40 two-position motor is that the series 40 is
• A.

A line voltage circuit

• B.

A fail-safe control circuit

• C.

Used mainly where hazardous conditions exist

• D.

Unusable when single-pole,double throw control of line voltage is required

• 47.
When the temperature increases above the set point in series 90 controller controlling a face andbypass damper cooling system, the motor will
• A.

Operate clockwise

• B.

Close the face dampers

• C.

Open the face dampers

• D.

Open the chilled water

• 48.
The rear pot in the series controller controls the
• A.

Face and bypass dampers

• B.

Reheat value

• C.

Temperature

• D.

Steam coil

• 49.
What meter should you use to check a two-posistion control without power?
• A.

Ammeter

• B.

Voltmeter

• C.

Ohmmeter

• D.

Anemometer

• 50.
What sould you do after installing a new eletrical control?
• A.

Give it a complete operational checkout

• B.

The resistance should be dropped

• C.

Handle control carefully

• D.

Replace the cover

• 51.
To calibrate a timed two-postion control system, adjust the
• A.

• B.

Differential

• C.

Limit stops in the motor

• D.

Resistance heater in the thermostat

• 52.
The failure of a control circuit to respond after calibration could be due to
• A.

A broken diaphragm

• B.

A short in the controller

• C.

• D.

An open in the motor windings

• 53.
To the lowest level of supervision, who can authorize you to work on energized circuit, if mission critical?
• A.

Chief of operations flight

• B.

HVAC foreman

• C.

Electrical foreman

• D.

Base civil engineer or equivalent

• 54.
Which Air Force publication gives you electrical safety requirements?
• A.

AFP 91-12

• B.

AFI 32-1064

• C.

AFI 32-1999

• D.

AETCI 32-101

• 55.
What would the resistance be for an electronic controller with a reference tempetature of 70*F, a reference of 100 ohms, and a rate of change of 2.2 ohms/degree that is sensing 65*F?
• A.

989 ohms

• B.

999 ohms

• C.

1011 ohms

• D.

1022 ohms

• 56.
Which sensor is used to measure temperature changes caused by stratification?
• A.

Ceiling diffuser

• B.

Averaging bulb

• C.

Insertion sensor

• D.

Humidity sensor

• 57.
Which electronic controllers may combine temperature and humidity measurements to measure heat content?
• A.

Electric to pneumatic controllers

• B.

Relative humidity controllers

• C.

Temperature controllers

• D.

Enthalpy controllers

• 58.
Use the following information to answer the next question: Controller = barber colman Vcal = 7.5 VDC (at midpoint) Span c = 3 VDC (6-9 direct current voltage (VDC) Tsp = 70*F TRc = 4*F Action = direct What should the output voltage (Vout) be if the sensor is sensing 68*F?
• A.

0 direct current voltage (VDC)

• B.

3 direct current voltage (VDC)

• C.

6 direct current voltage (VDC)

• D.

9 direct current voltage (VDC)

• 59.
Use the following information to answer the next question: Controller = barber colman Vcal = 7.5 VDC (at midpoint) Span c = 3 VDC (6-9 direct current voltage (VDC) Tsp = 70*F TRc = 4*F Action = direct What should the output voltage (Vout) be if the sensor is sensing 72*F?
• A.

0 direct current voltage (VDC)

• B.

3 direct current voltage (VDC)

• C.

6 direct current voltage (VDC)

• D.

9 direct current voltage (VDC)

• 60.
Upon calibrating a single input electronic controller with a decade box to simulate proper resistance, you notice that the voltage output isn't correct. What controller adjustment will remedy the problem?
• A.

Action

• B.

Set point

• C.

Throttling range

• D.

Variable resistance

• 61.
While calibrating a direct-acting electronic controller with a built-in sensor, if you increases the set point dial to equal half the amount of the throttling range, you provide an output voltage that
• A.

Decreases to half of the actuator range

• B.

Increases to half of the actuator range

• C.

Decreases to the full amount of the actuator range

• D.

Increases to the full amount of the actuator range

• 62.
Suppose you are calibrating an electronic controlling with integral control. After you have obtained the controller performance, what is the next thing you should do?
• A.

Calibrate the controller

• B.

Adjust the controller output

• C.

Turn the integral control action off

• D.

Replace the sensor with a variable resistor

• 63.
To test the integral action of an electronic controller, you should turn off the integral action and increase the V out. If the integral action is working, what will happen when you turn it back on?
• A.

The V out will stay the same

• B.

The V out will increase also

• C.

The V out will decrease

• D.

The V out will cycle

• 64.
The ratio or authority as used with the reset loop of a dual-input electronic controller determines the
• A.

Influence of the reset loop over the primary

• B.

Amount of integral control needed

• C.

Hot water reset performance

• D.

Calibration instructions

• 65.
• A.

Setting and or checking the throttling range

• B.

Current condition check of the output voltage

• C.

The ratio is set correctly

• D.

Current conditions check of the decade box

• 66.
What adjustment should you make if you find that the output voltage of a dual-input electronic controller is not what you predicted it would be?
• A.

Ratio dial

• B.

Throttling range

• C.

• D.

Set point dial

• 67.
You can check the voltage span of most electonic actuators by
• A.

Watching the system work

• B.

Operating the actuator from start to stop

• C.

Adjusting the set point dial

• D.

Changing the voltage output of the contoller

• 68.
What size energy monitoring and control system (EMCS) system has 50 to 600 points?
• A.

Large

• B.

Medium

• C.

Small

• D.

Micro

• 69.
What functions of the energy management software cycles HVAC equipment so only stored energy handles building load, but still maintains an occupancy comfort level?
• A.

Zero energy band

• B.

Optimum start

• C.

Optimum stop

• D.

• 70.
What function of the energy management software ensures that a minimum amount of heating or cooling energy is used to satisfy zone temperature requirements?
• A.

Zero energy band

• B.

Optimum start

• C.

Optimum stop

• D.

• 71.
What basic components make-up the diret digital controls (DDC) loop?
• A.

Controller area network (CAN),inputs and outputs

• B.

Personal computer, BAC network, and DCC controller

• C.

Process information, input parameters, and customer needs

• D.

Input from a sensor or device, a building automation controller, and controlled device

• 72.
What are the four basic methods of control in a direct digital contol (DDC) system?
• A.

Digital or analog outputs and digital or analog inputs

• B.

Digital outputs and digital or analog inputs, only

• C.

Digital or analog outputs and digital inputs, only

• D.

Digital outputs and digital inputs, only

• 73.
What sources of reheat do variable air volume (VAV) boxes use?
• A.

Steam and hot water

• B.

Hot water and electric

• C.

Electric and steam

• D.

None of the above

• 74.
What flow meter measures volume rate by inserting its free moving element into the water flow?
• A.

Differential-pressure

• B.

Mechanical

• C.

Centrifugal

• D.

Ultrasonic

• 75.
How do ultrasonic flow meters measure flow?
• A.

By measuring a free moving element into the flow

• B.

By measuring the difference across the orifice plate

• C.

By measuring the vertical plane of a venturi tube

• D.

By detecting changes in sonic paths within the fluid

• 76.
In critical buildings or locations, senors for differential-pressure flow meters should be calibrated every
• A.

Month

• B.

Three months

• C.

Six months

• D.

Year

• 77.
Perform recalibration procedures on direct digital control (DDC) systems according to the
• A.

Applicable air force instruction

• B.

Manufacturer's instruction

• C.

Local building codes

• D.

Craftsman's discretion

• 78.
To allow the passing of data to a local operator terminal or another controller, zone and system level controllers should be equipped with
• A.

Input/output boards

• B.

An analog/digital converter

• C.

A communications or access port

• D.

EEPROM

• 79.
Which test includes a sequence of operation demonstration and a control loop stability and accuracy demostration?
• A.

The basic field test

• B.

The performance verification test

• C.

The actuator range adjustment test

• D.

The application software test

• 80.
Whis test is essentially the same as the performance verification test?
• A.

Basic field test

• B.

Opposite season test

• C.

Operation of outputs test

• D.

Surge protection verification test

• 81.
HVAC fans noramlly provide firestats or smoke detectors and freezestats that provide for
• A.

Notification of emergency personnel

• B.

Control fire, smoke, and freezing

• C.

Fire and freeze suppression

• D.

Emergency fan shutdown

• 82.
How many degrees higher than the expected heating season maximum temperature should you set a supply duct firestat?
• A.

100*F

• B.

75*F

• C.

50*F

• D.

25*f

• 83.
The basic purpose of the mixed-air control system is to control the amount of
• A.

Return air brought into the system

• B.

Supply air brought into the system

• C.

Outside air brought into the system

• D.

Exhaust air brought into the system

• 84.
The purpose of the high-limit controller in a mixed-air control system is to
• A.

Open the return-damper when outdoor-air temperature is below its setpoint

• B.

Close the return-air damper when the outdoor-air temperature is above its setpoint

• C.

Close the outdoor-damper to minimum when the outdoor-air temperature is above its setpoint

• D.

Open the outdoor-damper to minimum when the outdoor-air temperature is below its setpoint

• 85.
If desired to maintain a constant temperature in the air leaving a coil, what type of coil control is used?
• A.

Zone control

• B.

Reset control

• C.

Reheat control

• D.

Discharge control

• 86.
What type of coil control provides for control of the coil from the controlled space?
• A.

Zone control

• B.

Reset control

• C.

Mixed-air control

• D.

Economizer control

• 87.
When controlling coils, it is sometimes desireable to use discharge control and reset the setpoint of the control loop as a function of another conditions. What might this condition or conditions be?
• A.

Mixed-air temperature

• B.

Return-air temperature

• C.

Outdoor-air or space temperature

• D.

Return-air or mixed-air temperature

• 88.
What is used in a humidity control subsytem to keep the humidity in the ductwork from getting to high?
• A.

Airflow switch

• B.

Normally closed humidifier

• C.

Low-limit humidity controller

• D.

High-limit humidity controller

• 89.
The purpose of an airflow switch in a humidity control subsytem is to
• A.

Shut the fan off

• B.

Lower the relative humidity in the duct

• C.

Protect the humidifier if the fan stops

• D.

Protect against putting water in the ducts

• 90.
Single-zone systems are typically used where space conditions can be properly controlled with
• A.

One sensor

• B.

Two sensors

• C.

Three sensors

• D.

Four sensors

• 91.
What would the output pressure of the temperature controller be if the sensor were sensing 70*F?
• A.

5 psi

• B.

8 psi

• C.

10 psi

• D.

13 psi

• 92.
Why are the mixed-air controller (MAC) and the temperature controller cooling (TCC) integrated to operate the controlled device (CD)?
• A.

If the zone temperature is low, TCC will override MAC and close dampers

• B.

If the zone temperature is low, TCC will override MAC and open dampers

• C.

If the zone temperature is high, MAC will override TCC and open the cooling valve

• D.

If the zone temperature is high, MAC will override TCC and close the cooling valve

• 93.
The purpose of HI in the terminal reheat system is to pass the signal from the
• A.

Mixed-air controller

• B.

Coil controller

• C.

Warmest zone

• D.

Coldest zone

• 94.
The mixed-air section for a variable air volume (VAV) system is identical to the one on a single-zone system, unless the
• A.

Cooling discharge temperature rises

• B.

Outdoor-air temperature is too low

• C.

Ventilation requirement drops

• D.

Ventilation load is constant

• 95.
On a variable air volume system uses a differential-pressure transmitter, what special component do you need to convert its signal to a proportional velocity pressure for an input signal to the controller?
• A.

Low-pressure selector

• B.

Square-root extractor

• C.

High-pressure selector

• D.

Velocity-pressure extractor

• 96.
With a multizone system, what controls the temperature to each zone?
• A.

The output of the hot-deck controller

• B.

The output of the cold deck

• C.

The mixed-air section

• D.

Zone mixing dampers

• 97.
The coil discharge temperature for a mulitzone system is based on the
• A.

Zones that have the smallest heating and cooling loads

• B.

Zones that have the largest heating and cooling loads

• C.

Temperature of the hot decks and cold decks

• D.

Number of zones the system is operating

• 98.
An efficient multizone system controls the coils by using the
• A.

Furthest of the zone controllers

• B.

Zone controllers through a discriminator

• C.

Hot-deck controller with the reheat controllers

• D.

Mixed-air controller through a high-pressure selector

• 99.
In which troubleshooting step would you identify the type of system?
• A.

Isolation

• B.

Diagnosis

• C.

Localization

• D.

Sectionalization

• 100.
Which troubleshooting step are you using when you divide the section in half to locate the trouble?
• A.

Isolation

• B.

Diagnosis

• C.

Localization

• D.

Sectionalization

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