Term
| The human body gives off heat by which of the following? |
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Definition
convection
radiation
conduction |
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Term
| How many Btus are required to change one pound of ice at 20 degrees F to steam at 220 degrees F? |
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Definition
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Term
Of the following choices which is the warmest temperature?
20 C
303 K
501 R
77 F |
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Definition
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Term
| Temperature is an indication of the |
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Definition
| amount of molecular activity in the material |
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Term
| At standard conditions water will boil at? |
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Definition
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Term
| The standard atmospheric pressure at sea level is? |
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Definition
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Term
| Pure water boils at a temperature of 212ºF at which of the following standard conditions? |
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Definition
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Term
| The temperature on the Fahrenheit scale where all molecular activity stops is? |
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Definition
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Term
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Definition
| pounds per square inch absolute gauge |
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Term
The amount of heat needed to change the temperature of a substance will vary with the type of substance.
This heat quality is called of the substance? |
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Definition
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Term
| A Bourdon tube is often found in a ? |
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Definition
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Term
| If the temp remains constant and the volume that a gas occupies increases, the pressure will ? |
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Definition
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Term
The volume of gas varies inversely with the absolute pressure, provided the temp remains constant.
This is called? |
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Definition
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Term
At a constant pressure, the volume of a gas varies as to the absolute temp and at a constant volume the pressure of the gas varies directly with the absolute temp.
This is known as? |
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Definition
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Term
The total pressure of a confined mixture of gases is the sum of the pressure of each of the gases in the mixture.
This is known as |
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Definition
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Term
| One watt of electrical energy is equal to ? |
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Definition
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Term
| A solid material exerts a pressure or force? |
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Definition
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Term
| A liquid material exerts a pressure or force? |
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Definition
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Term
| A vapor material exerts pressure or force? |
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Definition
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Term
| Refrigeration can be described as? |
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Definition
| The process of removing heat from a place where it is not wanted to a place where it makes little or no difference. |
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Term
| The pressure in a refrigeration system is changed in the? |
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Definition
| compressor and expansion device |
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Term
| The refrigerant in a refrigeration system changes state in the ? |
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Definition
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Term
| At what location or locations in a refrigeration system does the saturation pressure correspond to the saturation temperature? |
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Definition
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Term
| Which of the following refrigerants has the lowest boiling temperatures at atmospheric pressure? |
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Definition
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Term
| What happens when room temp soda is poured into a glass of ice? |
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Definition
| The ice melts because it is absorbing heat from the soda. |
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Term
| Ice melts in iceboxes because? |
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Definition
Heat flows through the insulated walls
Heat enters when the door is opened
Heat enters when warm food is placed in the icebox. |
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Term
| High temp refrigeration is that produced by? |
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Definition
| an air-conditioning system |
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Term
| A ton of refrigeration is equal to ? |
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Definition
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Term
| The evaporator in a refrigeration system? |
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Definition
| absorbs heat from the product to be cooled |
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Term
| The compressor in a refrigeration system? |
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Definition
| Pumps the refrigerant throughout the system |
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Term
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Definition
| rejects the heat from the refrigerant |
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Term
| Reciprocating compressors have? |
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Definition
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Term
| Good ventilation is important when working around refrigeration equipment because modern refrigerants? |
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Definition
| are heavier than air and may displace the oxygen around you. |
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Term
| The law requires technicians to recover refrigerant from all refrigeration systems so that they? |
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Definition
will not be released into the atmosphere
may be used again
may be reclaimed for future use |
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Term
When a refrigerant enters the compressor, it is a ?
and when it leaves the compressor, it is a ? |
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Definition
Low pressure low temperature superheated vapor,
high pressure high temperature superheated vapor |
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Term
| If a technician needed 5/8" ACR for an installation and was located near only a plumbing supply house, what size and type of pipe should he ask for? |
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Definition
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Term
| When soldering, why should flux be used? |
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Definition
It helps prevent oxidation
It helps keep pipes clean
It helps solder flow easier |
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Term
| When soldering, flux should be applied to ? |
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Definition
| The male part of the joint only. |
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Term
| Pipe threads are standardized by the A.N.S, A.N.S. stands for? |
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Definition
| American National Standard |
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Term
| When joining steel pipe, the following should be applied to the threads before connecting? |
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Definition
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Term
| 95/5 solder should be used? |
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Definition
| on the low side of the system. |
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Term
| The size indicated for the diameter of type L copper tubing used for plumbing is the approximate? |
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Definition
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Term
| The size indicated for the diameter of ACR copper tubing is the approximate? |
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Definition
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Term
| The maximum temp at which soft soldering is done is ? |
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Definition
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Term
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Definition
| higher temps than soldering |
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Term
| Filler materials used in the Brazing of copper joints are composed of what? |
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Definition
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Term
| When soldering or brazing, the solder is? |
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Definition
melted by heat from the tubing and fitting
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Term
| Pipe threads, when used on pipe that will contain liquid or vapor under pressure? |
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Definition
are tapered
should have at least seven perfect threads
generally have a V shape |
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Term
| The proper type of flame from an oxy-acetylene torch for silver brazing is ? |
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Definition
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Term
| For cleaning ACR copper tubing before soldering, a material that can be used is ? |
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Definition
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Term
| Molten solder flows between the two base metals being soldered because? |
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Definition
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