For Top-notchers 1-200+

_______ is a method used to reduce the dehydration of sensitive fruits and vegetables during the chilling process. A. B. C. D.

Vacuum chilling Water chilling Ice chilling None of the above

As a liquid changes phase to a solid, its entropy _______ A. B. C. D.

Increases Decreases Remains the same constant

The vaporization process that occurs when the vapor pressure of a substance is equal to the atmospheric pressure is A. B. C. D.

Evaporation Sublimation Boiling Condensation

In an isobaric process, changes in pressure can be caused by changes in A. B. C. D.

Temperature Volume Density None of the above

The component in the refrigeration cycle that expands refrigerant is called the A. B. C. D.

Condenser Metering device Compressor Evaporator

The volume of vapor that the compressor must handle per minute per ton _____ as the vaporizing temperature increases. A. B. C. D.

Increases Remains the same Decreases Constant

Pressure drops cause the saturation temperature of the fluid to ____. A. B. C. D.

Increase Decrease Remain the same Decreases by 10%

Which of the following is not a hydrocarbon refrigerant? A. Propane B. Isobutene C. Butane D. Inane

A mixture of two or more refrigerants is called ____ A. Zeotrope B. Halocarbon C. Desicant D. Absorbent

Which evaporator design incorporates secondary surface heat transfer? A. Bare – tube B. Finned – tube C. Embossed surface-plate D. A and B

What type of forced convection unit cooler is used in vegetable storage applications that require a velocity of approximately 120 m/min? A. Low velocity B. High velocity C. Medium velocity D. Standard velocity

What is the range of relative humidity that can be maintained with a forcedconvection evaporator operating with a 15degree F TD? A. 91-95% B. 81-85% C. 86-90% D. 76-80%

_____ decreases the volumetric efficiency of a compressor. A. Increasing the suction pressure B. Decreasing the suction pressure C. Decreasing the discharge pressure D. Reducing the clearance volume

Which power value is not affected by changes in the compression efficiency? A. Indicated power B. Shaft power C. Compressor power D. Friction power

As the temperature of the evaporator increases, the sonic velocity of the vapor _____ . A. Increases B. Decreases C. Remains the same D. Varies

The type of compressor that incorporates a volute is a ____ compressor. A. Roller B. Scroll C. Rotary vane D. Centrifugal

The resistance that a fluid offer to flow as a consequence of its internal friction forces is called A. Viscosity B. Pour point C. Viscosity index D. Lubricity

Reducing refrigerant migration during the off cycle _____ oil foaming. A. Increases B. Decreases C. Has no effect on D. Varies

Which of the following strategies will reduce oil foaming in a system? A. Pump-down cycle B. Oil additives C. Crankcase heaters D. All of the above

As the altitude of a forced air-cooled condenser increases, the surface area of the coil or volume flow rate of the fan must _______ A. Increase B. Decrease C. Remain the same D. Vary

Reducing the design temperature of an air cooled condenser _____ the amount of heat it can reject to the ambient. A. Increases B. Decreases C. Will not change D. Varies

Reducing the fouling in a water-cooled condenser _____ its rate of heat transfer. A. Increases B. Decreases C. Will not change D. Varies

The surface area of the tubes in a watercooled condenser must _____ if the LMTD is less than the design value and the saturated temperature is to remain constant A. Be increased B. Remain the same C. Be decreased D. Vary

Chemicals are not added to tower water to reduce -_____. A. Algae B. Foaming C. Cycles of concentration D. Bacteria

As the amount of saturated air drawn back into a tower decreases, the tower approach ______ A. Increases B. Remains the same C. Decreases D. Varies

As the cycle of concentration in a tower of evaporative condenser increases, the potential for scale formation on hot surfaces _______ A. Increases B. Remains the same C. Decreases D. Varies

The ____ can only be effectively employed in industrial processes that have relative constant refrigeration load A. Hand expansion valve B. Thermal expansion valve C. Automatic expansion valve D. Electric expansion valve

The device used to minimize the effects of a large pressure drop across the evaporator is called an A. Diaphragm B. External equalizer C. Internal equalizer D. None of the above

The device used to transfer forces across a sealed boundary is called a A. Seat B. Port C. Needle D. Diaphragm

The maximum operating pressure of an evaporator can be limited through the use of a ____ sensing bulb. A. Liquid cross-charge B. Straight gas charge C. Gas cross-charge D. B and C

As the amount of superheat in a system using a straight liquid-charged sensing bulb increases, the needle of the TXC ____ the flow of the refrigerant. A. Increases B. Does not change C. Decreases D. Varies

Which of the following is not a consideration when Selecting a cap tube for an application? A. Condenser pressure B. Heat of compression C. Evaporator pressure D. Flow rate of refrigerant

As the subcooling of the refrigerant increases, the flow through a high side float _____ A. Increases B. Remain the same C. Decreases D. Varies

Refrigerant piping is designed and installed in a manner that ______ A. Minimizes refrigerant pressure losses in the connecting piping B. Ensures the continuous return of oil to the compressor crankcase C. Prevents liquid refrigerant from entering the compressor during startup D. All of the above

A receiver tank is used to _____ A. Hold the excess refrigerant during lighter loads B. Collect oil from the base of a riser C. Separate liquid from vapor refrigerant D. All of the above

Which style valve produces the least change in the saturation temperature of refrigerant flowing through it? A. Globe B. Check C. Gate D. Angle

Which type of low side pressure regulator is used to prevent a compressor from overloading? A. Low side float B. EPR C. SPR D. OROA

Which of these devices does not operate in response to a change in its inlet pressure? A. EPR B. ORI C. SPR D. A and C

Which of the following system characteristics is not needed when selecting the proper water regulating valve for a water-cooled application? A. The necessary flow rate of water B. The condensing pressure C. The available water pressure drop D. Minimum ambient temperature

The device used in a control loop to measure the controlled variable is called a ______ A. Controlled device B. Controller C. Summing junction D. Sensor

Which type of control requires a controls differential? A. Throttling B. Modulating C. Two – position D. A and B

When the pressure on the high pressure side of the system decreases below the high limit set point ____ the control differential, an autoresetting high pressure control closes the control circuit to the condensing unit, enabling the compressor A. Plus B. Times C. Minus D. Divide

A hot gas bypass valve responds to changes in the system’s ____ pressure. A. Liquid line B. Discharge C. Suction D. None of the above

As the difference between the cut-in and cut-out pressures increases, ________. A. The range increases and short cycling increases B. The range increases and short cycling decreases C. The range decreases and cycling is unaffected D. The range decreases and short cycling increases

As the load of a refrigeration system increases, the on cycle of the compressor _______. A. Increases B. Remains the same C. Decreases D. Approaches zero

Intercoolers are devices used in direct staged system to _______ A. Increase the temperature of the liquid refrigerant leaving the condenser B. Reduce the pressure of the liquid refrigerant leaving the condenser C. Reduce the pressure of the vapor entering a higher stage compressor D. Reduce the temperature of the vapor entering higher stage compressor

The type of unit that incorporates several stages of compression using different refrigerants is called a ____ system, A. Direct expansion B. Absorption C. Cascade D. Direct stage

The weak solution in an absorber develops in the ______ A. Evaporator B. Absorber C. Condenser D. Generator

Highest pressure drop in a vaporcompression refrigeration cycle occurs in the : A. Compressor B. Evaporator C. Compressor D. Expansion valve

A residential refrigerator is similar in purpose and operation to a commercial _______. A. B. C. D.

Walk – in Reach – in Display case Self-service display case

Which of the following characteristics of early refrigeration systems still applies to today’s units? A. B. C. D.

Bulky Relatively expensive Poor efficiency All of the above

Mechanical refrigeration systems make it possible to A. Process, freeze, store, transport and display perishable products B. Make buildings inhabitable in the summer heat C. Develop new chemicals and other new useful materials D. All of the above

The air conditioning system for cabins on a luxury ocean liner belongs to the _____ category. A. B. C. D.

Marine and transportation refrigeration Commercial air-conditioning Industrial refrigeration None of the above

Which of the following microorganism is most affected by the movement of air? A. B. C. D.

Mold Enzyme Yeast Bacteria

The reproductive activity of microorganisms is increased by A. Lowering the temperature of the environment B. Increasing the temperature of the environment C. Decreasing the temperature of the environment D. All of the above

Which of the following is not a category of refrigeration applications? A. B. C. D.

Domestic refrigeration Commercial refrigeration Industrial refrigeration Transportation air-conditioning

Which of the following is not a method of food preservation? A. B. C. D.

Refrigeration Canning Dehydrating Grilling

Which of the following is not a step in preparing vegetables for frozen storage? A. B. C. D.

Cleaning Chilling Coating with syrup Blanching

Wrapping and refrigerating food products extends the storage life A. B. C. D.

Meats Fruits Vegetables All of the above

Which of the following devices should be used to measure a pressure of 90 kpa A. B. C. D.

Pressure gauge Compound gauge Barometer All of the above

Frozen storage chamber temperature set points are usually _______. A. B. C. D.

5 degree F 0 degree C -20.5 degree C A and B

Which of the following variables is most often maintained by a commercial air – conditioning unit? A. B. C. D.

Temperature Air purity Air motion Humidity

A disadvantage of sharp freezing is the A. Increase in juice losses upon thawing B. Increase in the size of the ice crystals that form in the food C. Decrease in quality experienced by the food during the freezing D. All of the above

Which of the following sequences accurately indicates the responses that occur when heat is transffered from a gas? A. Sensible heat of solids, latent heat of fusion,sensible heat of vapors, latent heat of vaporization B. Sensible heat of vapors, latent heat of fusion, sensible heat of liquid, latent heat of vaporization C. Sensible heat of vapors, latent heat of vaporization, sensible heat of liquids, latent heat of fusion, sensible heat of solids D. Latent heat of vaporization, sensible heat

As the pressure of a vapor increases, the amount of work it can do to increase and its enthalpy ______ A. B. C. D.

Increases Decreases Remains the same Constant

As a gas is heated in an isometric process, its volume __ A. B. C. D.

Increases Decreases Remains the same Increase by 20%

The height of the mercury column in a barometer placed on a mountain with a local pressure of 13.5 psi will be A. B. C. D.

25 inches 698 mm 93.1 kpa All of the above

If air, hydrogen, oxygen and carbon dioxide undergo adiabatic expansion process having identical initial and final values of pressure and volume, which gas will do more work on the surroundings? A. B. C. D.

Air Hydrogen Carbon dioxide Oxygen

Boyle’s law states that pressure and volume changes in gas process are ____ related. A. B. C. D.

Directly Not Inversely Ideally

The refrigeration effect per unit mass of refrigerant circulated ______ as the vaporizing temperature increases. A. B. C. D.

Increases Remains the same Decreases Increase by 20%

Which of the following process does not alter the kinetic energy level of a substance? A. B. C. D.

Fusion Adding sensible heat to solid Adding sensible heat to liquid Superheating vapor

Subcooling increases the _____ of the refrigeration cycle. A. B. C. D.

Capacity Mass flow rate Refrigeration effect Volume flow rate

The volume of refrigerant vapor compressed per unit capacity _____ as the condensing temperature increases. A. B. C. D.

Increases Remains the same Decreases Increase by 10%

As a liquid changes phase to a vapor, its enthalpy ______ A. B. C. D.

Increases Decreases Remains the same constant

As the volume of an isothermal expansion process approaches its final value, the rate of change in the system pressure A. B. C. D.

Increases Remains constant Decreases None of the above

Which of the following is not a form of moisture loss from frozen food products? A. B. C. D.

Sublimation Spoilage Freezer burn Dehydration

The COP and the efficiency of a refrigeration cycle _____ as the vaporizing temperature increases. A. B. C. D.

Increases Remains the same Decreases Constant

Which of the following is not an industrial refrigeration application? A. B. C. D.

Meat display cases Ice manufacturing plants Large food-packing plants Creameries

The condenser is designed to transfer ______ heat to the condensing medium that was absorbed in the evaporator A. B. C. D.

More The same Less Constant

The freezing method that uses a brine to directly absorb heat from the food product is called _____ freezing. A. B. C. D.

Brine Contact Immersion Blast

Which of the following factors is not used to determine the toxicity of a refrigerant? A. Exposure time B. Concentration C. The amount of refrigerant in the system D. Its latent heat of vaporization

The approximate storage life of fresh strawberries is ____ A. B. C. D.

5 to 7 weeks 1 to 3 weeks 7 to 10 days None of the above

Which of the following vapor-compression cycle processes is adiabatic? A. B. C. D.

Vaporization Condensing Throttling Superheating

A medium velocity dry surface air-cooling coil having a volume flow rate of 1,000 cfm would have a face area of ______ ? A. 1 B. 3 C. 2 D. 4

ft2 ft2 ft2 ft2

As the volume of a gas decreases, its specific gas constant A. B. C. D.

Increases Decreases Remains the same Decreases by 10%

Vapors do not behave as ideal gases because they experience A. B. C. D.

Friction Volume Temperature changes All of the above

The heat of compression ______ as the suction vapor becomes superheated. A. B. C. D.

Increases Decreases Remains the same No effect

The heat content of a refrigeration cycle ____ when a liquid suction line heat exchanger is installed. A. B. C. D.

Increases Decreases Remains the same Increases by 10%

As the value of SHR of a process increases, the temperature difference between the entering and leaving airstream ________ . A. Increases B. Decreases C. Remains the same D. Varies

Which type of brine is used in applications where it may come in contact with food? A. Calcium chloride B. Propylene glycol C. Baudelot D. Sodium chloride

The component in the refrigeration cycle that is used to store refrigerant is called the ______ A. B. C. D.

Receiver Metering device Compressor Evaporator

The final temperature of an isobaric process decreases if the system work is a ______ quantity and the surroundings transfer heat to the system A. B. C. D.

Positive Linear Negative Nonlinear

What is the concentration of calcium chloride by mass needed to obtain a freezing (crystallization) temperature of 13 degree F? A. 15.5% B. 14.5% C. 21.5% D. Over 30%

The vaporization process that occurs at temperatures below the triple point of a substance is ______ A. B. C. D.

Evaporation Sublimation Boiling Condensation

Which evaporator circuit configuration is less effective when used in dry-expansion feed applications? A. Single B. Crossflow C. Split D. Counterflow

Pressure drops cause the specific volume of a vapor to ________. A. B. C. D.

Increase Decrease Remains the same No effect

As a gas is cooled in an isobaric process, its volume ____ A. B. C. D.

Increases Decreases Remains the same Constant

The type of compressor that develops the least amount of vapor pulses is a _____ compressor A. Roller B. Scroll C. Rotary vane D. Centrifugal

The scale factor for hard water used in a condenser with a water velocity of 4 ft/sec is _____ A. 0.003 B. 0.005 C. 0.002 D. None of the above

An externally equalized valve should be used whenever the pressure drop through the evaporator produces a greater than _____ change in the saturation temperature A. 1.2 degree F B. 1.2 degree C C. 1 degree F D. None of the above

As the amount of scale on the refrigerant tubes of an evaporative condenser increase, the refrigeration effect of the system ______ A. Increases B. Remains the same C. Decreases D. Varies

Which of the following is not a plant, animal or fungi? A. B. C. D.

Mold Enzyme Yeast Bacteria

As the condensing temperature of a centrifugal system decreases the power required by the compressor _____ A. Increases B. Decreases C. Remains the same D. Varies

Which type of metering device does not require a critical refrigerant charge? A. Low side float B. Short-tube restrictor C. High side float D. Capillary tube

Which of the following does not decrease the volumetric efficiency of a compressor? A. Decreasing the discharge pressure B. Decreasing the suction pressure C. Increasing the compression ratio D. Increasing the cylinder heating

A measure of the amount of water vapor that can be absorbed by the atmosphere under its current conditions is called _____ A. DB temperature B. WB temperature C. DP temperature D. Relative humidity

Which of the following does not increase the change of a compressor surging? A. Increasing the discharge pressure B. Increasing the suction pressure C. Decreasing the compression rotational speed D. Decreasing the evaporator temperature

If the required capacity of a coil is less than its rated capacity the TD will? A. Increase B. Decrease C. Remain the same D. Vary

The type of compressor that has a single reciprocating blade is a ____ compressor. A. Roller B. Scroll C. Rotary vane D. Centrifugal

As a gas is heated in a an isothermal process, its volume A. B. C. D.

Increases Decreases Remains the same Constant

If the thermal capacitance of a process is low, the control differential must be _____ to prevents short – cycling of the compressor. A. Increased B. Decreased C. Changing the differential has no bearing on short – cycling D. Identical

The polytropic exponent approaches one when the change in the process _______ approaches zero. A. B. C. D.

Temperature Volume Pressure Work

Oil foaming is a consequence of A. Oil temperature B. Refrigerant solubility C. Refrigerant pressure D. Oil viscosity

As the rotational speed of a rotary compressor increases, its capacity ______ A. Increases B. Decreases C. Remains the same D. Varies

The ratio of the current partial pressure of the water vapor in the atmosphere to the saturation pressure of the water vapor at the current DB depression is called the ______ A. DB depression B. WB temperature C. DP temperature D. Relative humidity

Superheating ____ the possibility of sending liquid into the compressor. A. B. C. D.

Increases Decreases Does not affect Fixed

Tower fill is not used to increase the _____ A. Surface area of the water B. Time the water is exposed to the air C. Velocity of the atmosphere D. Tower drift

As the length of the tubes in a chiller barrel increase, the pressure drop across the inlet and outlet of the barrel. A. Increases B. Decreases C. Remains the same D. Varies

As the evaporator temperature of a system using a straight liquid –charged sensing bulb decreases, the superheat of the TXV _____ A. Increases B. Remains constant C. Decreases D. Varies

Which of the following refrigerants is most hazardous? A. R-113 B. R-717 C. R-11 D. R-152a

A residential dehumidifier is an application to the ___ category. A. B. C. D.

Domestic refrigeration Commercial refrigeration Domestic air-conditioning Industrial refrigeration

Which of the following changes may increase the flashing in a liquid line? A. Increasing the subcooling B. Increasing the pipe diameter C. Decreasing the pipe length D. Decreasing the line diameter

Which sensing bulb charge is used in low and medium temperature applications that do not require pressure limiting characteristics? A. Liquid cross-charge B. Gas cross-charge C. Straight liquid charge D. Straight gas charge

The mass flow rate of refrigerant per unit capacity ____ as the condensing pressure decreases. A. B. C. D.

Increases Remains the same Decreases No effect

Which of the following systems has the most complicated oil return system? A. Direct staged B. Ammonia absorption C. Cascade D. Lithium bromide absorption

Which of the following is not considered when determining the pressure drop available for a TXV? A. Distributor B. Changes in elevation C. Refrigerant pressure D. Filters

Which type of intercooler mixes the liquid refrigerant from the condenser with the discharge vapor of the lower stage compressor? A. Open B. Dry expansion C. Shell and coil D. None of the above

A device used as a visual indicator of the charge in a refrigeration system is a _____ A. Slight glass B. Drier C. Pressure switch D. Strainer

Providing clean, filtered air for trouble free operation of equipment and instrumentation is a function of ______. A. B. C. D.

Industrial refrigeration process Industrial air-conditioning process Commercial air-conditioning process Comfort air-conditioning process

An evaporator in refrigeration unit makes use of which heat transfer modes? A. B. C. D.

Conduction Radiation Convection All of the above

The mechanical efficiency of the compressor ___ as the compressor load increases _____. A. Increases B. Decreases C. Remains the same D. Varies

The difference between the saturation pressure in the evaporator and that in the condenser _____ as the suction temperature decreases A. B. C. D.

Increases Remains the same Decreases Constant

As fluids flow through a pipe, their potential energy ____ A. B. C. D.

Increases Decreases Remains the same No effect

Which of the following is not a disadvantage of the refrigeration method of food preservation A. The process must begin very soon after the fool is harvested B. The vitamin content of the food is maintained C. The refrigeration process must be continuous until the food is consumed D. This method requires relatively expensive and bulky equipment

Which of the following high-side pressure regulators operates on an increase in differential pressure A. ORI B. ODO C. OROA D. None of the above

If a compressor has more capacity than the evaporator, the saturated suction pressure will be _____ design conditions. A. Greater than B. The same as C. Less than D. Identical

The electric meter on a home or building measures the amount of _______ that was converted over the billing period. A. Work B. Energy C. Power D. None of the above

As the pressure drop across the liquid line decreases, the refrigeration effect of the cycle _____. A. B. C. D.

Increases Decreases Remains the same No effect

The type of compressor that uses ring valves is a _____ compressor A. Roller B. Scroll C. Rotary vane D. Reciprocating

Which of the following conditions destroys molds? A. Exposure to ultraviolet lights B. Lowering its temperature C. Reducing the relative humidity if its environment D. All of the above

Which pressure regulating valve maintains a low limit in an evaporator? A. OROA B. SPR C. ORI D. EPR

Which type of metering device is used in heat pump applications? A. Low side float B. Short tube restrictor C. High side float D. Capillary tube

The saturated suction temperature used in the selection of a compressor corresponds to the pressure of the vapor at the _____. A. Inlet of the compressor B. Evaporator inlet C. Outlet of the evaporator D. Inlet of the condenser

Which of the following is not a process characteristic controlled in long-term storage chambers? A. B. C. D.

Temperature Air velocity Humidity Air purity

Which refrigerant is not used in the high stage of a cascade system? A. R-23 B. R-717 C. R-22 D. R-134a

Desicants are used to remove ____ from refrigerants. A. Oil B. Moisture C. Acids D. All of the above

Discharge line lubricant separators are not usually employed in systems _______. A. Operating at low temperatures B. Utilizing non-oil returning evaporators C. Systems with a small range of capacity control D. They are used in all of the above systems

Which method of compressor capacity control does not produce a reduction in condensing power requirements when the compressor capacity is decreased? A. Cylinder unloading B. Multiple compressor C. Variable speed drives D. Hot gas bypass

The flow cycle for the refrigerant in an absorption chiller is _____ A. From the condenser to the absorber to the evaporator to the generator B. From the condenser to the generator to the absorber to the evaporator C. From the condenser to the evaporator to the absorber to the generator D. From the condenser to the absorber to the generator to the evaporator

Which of the following system changes has the least effect on the flow rate through a stationary short tube restrictor? A. Rise in condenser pressure B. Increase in subcooling C. Decrease in evaporator pressure D. Fixed condenser pressure

Which of the following evaporator feed methods produces the greatest tube surface wetting without the use of a liquid pump? A. Dry-expansion B. Circulated refrigerant C. Flooded D. Overfeed

Energy added to a vapor is known as A. B. C. D.

Latent heat of vaporization Superheat Sensible heat of vapor B and C

The type of compressor that uses compliant gate rotors is a _____ compressor. A. Roller B. Scroll C. Rotary vane D. Screw

Which defrost method is commonly used small commercial applications where ice forms on the evaporators surfaces? A. Off – cycle B. Electric C. Hot gas D. All of the above

The refrigerant in absorber releases its high pressure latent heat of condensation in the ______ A. Evaporator B. Absorber C. Condenser D. Generator

Which type of metering device has a critical length dimension? A. Low side float B. Short tube restrictor C. High-side float D. Capillary tube

Which method of leak testing can be used with hydrocarbon refrigerants? A. B. C. D.

Soap bubbles Halide torch Electronic detectors A and C

As the saturation pressure of the refrigerant in the evaporator increases, the refrigeration effect of the process ______ A. B. C. D.

Increases Decreases Remains the same None of the above

Which type of metering device can be used in packaged air-conditioning units? A. Short tube restrictor B. A and C C. Capillary tube D. Low side float

Heat transfer that occurs primarily by conduction is used for ______ freezing processes A. B. C. D.

Air blast Immersion Indirect contact All of the above

Which type of metering device can be used in multiple flooded evaporator applications? A. Low-side float B. Short tube restrictor C. High-side float D. Capillary tube

The change in kinetic energy of a gas process _____ as the change in temperature of the process path increases A. B. C. D.

Increases Remains constant Decreases None of the above

Which of the following methods cannot be used for oil level equalization between multiple compressors operating in parallel? A. A crankcase pressure equalizing tube along with an oil equalizing tube B. Oil level controls on each crankcase fed from an oil receiver C. A single pipe located below the oil level in the crankcases D. All of the above

The type of compressor that uses slide valves to vary capacity is a _____ compressor. A. Roller B. Scroll C. Rotary vane D. Centrifugal

Which type of metering device can be used to create a check valve in a heat pump system? A. Low side float B. Short tube restrictor C. High side float D. Capillary tube

Which fitting produces the greatest pressure drop? A. 90 B. 90 C. 45 D. 45

degree degree degree degree

standard elbow street ell standard elbow steet ell

The refrigerant in an absorber changes from a vapor to a liquid in the ______ A. Evaporator B. Absorber C. Rectifier D. Generator

The quantity of heat rejected as the condenser per unit capacity per minute ___ as the vaporizing temperature in the evaporator decreases. A. B. C. D.

Increases Remains the same Decreases Constant

The quantity of energy absorbed by a unit mass of refrigerant in the evaporator is called A. B. C. D.

Capacity Mass flow rate Refrigeration effect Volume flow rate

As a general rule, the external equalizer connection is made on the suction line approximately ________ Beyond the expansion valve’s sensing bulb in the direction of the compressor. A. 24 in B. A or C C. 60 cm D. Neither of the above

Which of the following system characteristics has the least effect on the flow rate through a stationary short tube restrictor? A. Condenser pressure B. Orifice size C. Subcooling D. Fluid direction

As the condensing temperature increases, the cycle’s refrigeration effect ______. A. B. C. D.

Increases Remains the same Decreases No effect

Which of the following is not a normal function of lubricating oil used in refrigeration system? A. Develop hydrodynamic seal B. Transport debris C. Transfer heat D. Increase wear

The saturation temperature of the water vapor in the atmosphere is called A. DB temperature B. WB temperature C. DP temperature D. Relative humidity

The condenser of a commercial display case that is located within the unit is called A. B. C. D.

Remote the unit is called Local condenser Integral condenser B and C

During the compression process, the internal energy of refrigerant vapor A. B. C. D.

Increases Decreases Remains the same None of the above

The mass flow rate of refrigerant _____ as the saturation temperature of the evaporator decreases. A. Increases B. Decreases C. Remains the same D. Varies

The level of solubility of refrigerants in an oil is a function of temperature and ____ . A. Viscosity B. Dielectric strength C. Pour point D. None of the above

Spiral belt freezing units are typically used for _____ freezing processes. A. B. C. D.

Air blast Immersion Indirect contact All of the above

The component in the refrigeration cycle that has a negative heat transfer value is the A. B. C. D.

Condenser Metering device Compressor Evaporator

The lowest temperature at which an oil can flow is called a. b. c. d.

Viscosity Pour point Viscosity index Lubricity

As the TD of the evaporator decreases, the amount of moisture that condenses on the coil surfaces ____________. A. Increases B. Decreases C. Remains the same D. fixed

Which of the following dry-expansion evaporator configurations is most efficient? A. Crossflow with distributor B. Counterflow with distributor C. Counterflow with header D. Crossflow with header

Which of the following is not a step in preparing fruit for frozen storage? A. B. C. D.

Cleaning Chilling Coating with syrup Blanching

As the amount of scale on the refrigerant tubes of an evaporative condenser increases, the amount of make up water ______ A. Increases B. Remains the same C. Decreases D. Varies

The entropy of a process in which an ideal gas experiences a reductions in its internal energy _____. A. B. C. D.

Increases Decreases Remains the same Constant

Which type of control requires a control differential? A. Throttling B. Modulating C. Two – position D. A and C

The specific heat of air is _____ that of water A. Greater than B. Equal to C. Less than D. Proportional

A smaller temperature difference between the refrigerant in the liquid line and that in the evaporator_____ the mass flow rate of refrigerant needed per ton of refrigeration effect. A. B. C. D.

Increases Remains the same Decreases Decrease by 10%

______ is one of the most common applications of mechanical refrigeration. A. B. C. D.

Preservation of perishable commodities Comfort air-conditioning Industrial refrigeration None of the above

A measure of the average thermal intensity of the gas and vapor molecules in the atmosphere is the ____ A. DB temperature B. WB temperature C. DP temperature D. Enthalpy

Which of the following liquid – chilling evaporator types incorporates crossflow heat exchange? A. Double – pipe B. Shell and tube C. Baudelot D. Flooded chiller barrel

Which of the following refrigerant groups denotes a more toxic vapor A. A3 B. A1 C. B3 D. A and B

The COP of a refrigeration process ___ with subcooling A. B. C. D.

Increases Decreases Remains the same Fixed

Which of the following oils is not normally used with HFC refrigerants A. Plyalphaolefin B. Napthenes C. Alkylbenzenes D. Polyglycosis

As the water temperature entering a water-cooled condenser decreases, the power drawn by the compressor _____ A. Increases B. Decreases C. Will not change D. fixed

The temperature difference of a watewater-cooled condenser is ______ that of a recirculated water system. A. Greater than B. Equal to C. Less than D. Fixed

As an oil-miscible refrigerant mixes with oil, the viscosity of the oil _____ . A. Increases B. Decreases C. Remains the same D. Fixed

_________ is a device used to remove acids from a system after a burn-out A. Receiver B. Suction filter-drier C. Suction line heat exchanger D. Oil separator

Loss of food juices by osmosis is a consequence of the ____ freezing processes. A. B. C. D.

Air blast Immersion Indirect contact All of the above

An electric device used to reduce foaming in a crankcase is a A. Solenoid valve B. Check valve C. Crankcase heaters D. All of the above

The component in the refrigeration cycle that subcools refrigerant is called the A. B. C. D.

Condenser Metering device Compressor Evaporator

The strong solution in absorber develops in the ___ A. Evaporator B. Absorber C. Condenser D. Generator

As the refrigeration load decreases, the amount of refrigerant catering throughflow receiver _______ A. Increases B. Remains the same C. Decreases D. Varies

Eutectic filled plate evaporators have a higher _____ Than evacuated plate evaporators. A. Mass B. Thermal acceptance C. Holdover capacity D. All of the above

Oil separators are used in systems where A. Oil return is likely to be inadequate B. Nonmiscible refrigerants are used C. The amount of oil in circulated is likely to be excessive D. All of the above

When a service technician place his/her hand on a suction line to check the operation of a system, he/she is using which heat transfer modes? A. B. C. D.

Conduction Radiation Convection All of the above

The society that sponsors research on refrigerants is called A. ASHRAY B. ASREA C. ASHRAE D. ARI

As the pressure drop in a liquid line increases, the flow of liquid refrigerant _____. A. B. C. D.

Increases Decreases Remains the same Decreases by 20%

The rate at which the viscosity of an oil changes as its temperature changes is called ____ A. Viscosity B. Pour point C. Viscosity index D. Floc point