Modern Ref. Chapter 4

Question 1

What is the purpose of a refrigeration system?

Answer 1

To transfer heat from one location to another.

Question 2

_____ is the ability to effect change in matter

Answer 2

Energy

Question 3

Potential energy is _______ energy

Answer 3

stored

Question 4

Name 5 types of energy

Answer 4

Chemical
Thermal
Light
Electrical
Mechanical

Question 5

What is the law of conservation of energy?

Answer 5

Energy can neither be created or destroyed, it is simply changed from one form to another

Question 6

What is density?

Answer 6

A substances mass per unit of volume (lb/ft^3)

Question 7

What is Avogadro’s law?

Answer 7

Different gases at equal temperatures, pressures, and volumes contain equal numbers of molecules.

Question 8

What is force?

Answer 8

Energy applied to matter that, unless counteracted y opposing forces, causes a change in the matters velocity.

Question 9

Si unit of force?

Answer 9

Newton (N)

Question 10

What is work?

Answer 10

Work is force multiplied by the distance through which it travels.

Question 11

Si unit of work?

Answer 11

joule (J)

Question 12

What is power?

Answer 12

the rate at which work is performed

Question 13

Si unit of power?

Answer 13

Watts (W)

Question 14

The temperature of melting ice in Fahrenheit and Celsius?

Answer 14

32 degrees Fahrenheit

0 degrees celsius

Question 15

The temperature of boiling water in Fahrenheit and Celsius?

Answer 15

212 degrees Fahrenheit

100 degrees Celsius

Question 16

What does absolute zero mean?

Answer 16

This is the temperature at which molecular motion stops. it is the lowest temperature possible.

Question 17

What are the Rankine and Kelvin scale?

Answer 17

These are two absolute zero temperature scales. One in Fahrenheit and one in Celsius

Question 18

What is ambient temperature?

Answer 18

The temperature of the air surrounding an object

Question 19

Radiation is the transfer of heat by ____

Answer 19

rays

Question 20

Three methods of heat transfer commonly used in comfort heating and cooling are:

Answer 20

Radiation, Conduction, and Convection

Question 21

Light generates more heat when striking through ____ coloured rough objects than when striking _____ coloured polished surfaces

Answer 21

dark, light

Question 22

Superheat is the difference in temperature between a vapour and its _________ _____

Answer 22

condensation point

Question 23

To calculate a vapours superheat, subtract its _______ ____ from its measured temperature.

Answer 23

condensation point

Question 24

Heat always flows from a ______ substance to a _____ substance

Answer 24

warmer to cooler

Question 25

The ____ system is the modern version of the metric system?

Answer 25

Si system?

Question 26

The two main classifications of energy are?

Answer 26

potential and kinetic energy

Question 27

The law of conservation of energy states that:

Answer 27

Energy can neither be created or destroyed

Question 28

The weight of a substance is defined as the:

Answer 28

force of gravity acting on a substance

Question 29

The density of a substance is defined as the mass of the substance

Answer 29

divided by its volume

Question 30

If a substance has a specific gravity less than 1.0, it means that the substance is _____

Answer 30

less dense than water

Question 31

Objects that float on water have a specific gravity ____ ____ one

Answer 31

less than

Question 32

Relative density is defined as the ratio of the mass of a certain volume of a gas compared to the mass of an equal volume of hydrogen. Knowing this concept and that density is mass per volume, a heavy gas would then have a density _______

Answer 32

greater than 1

Question 33

____ is the rate at which work is performed

Answer 33

power

Question 34

Temperatures measured on the ____ scale can be converted to Fahrenheit temperatures by subtracting 460F

Answer 34

Rankine

Question 35

The ___ of a substance is the amount of heat added or released to change the temperature of 1lb of the substance by 1 degree F or 1kg of the substance by 1 k.

Answer 35

specific heat capacity

Question 36

Enthalpy is the ______

Answer 36

total amount of heat in a substance calculated from an accepted reference temp.

Question 37

______ is the method by which heat is transferred from one substance to another through a circulating medium such as air or water

Answer 37

Convection

Question 38

Heat energy can be categorized as latent heat and ____heat.

Answer 38

sensible

Question 39

Latent heat is added to the substance that _____

Answer 39

causes the substance to change state

Question 40

A ton of refrigeration effect is defined as the:

Answer 40

Amount of heat energy absorbed when a ton of ice melts during one 24-hour day.