from the book (Reference_Heat Transfer (Cengel) 2nd ed)

Question 1

is the transfer of energy from the more energetic particles of a
substance to the adjacent, less energetic ones as a result of interactions between the particles.

Answer 1

conduction

Question 2

is the mode of heat transfer between a solid
surface and the adjacent liquid or gas that is in motion, and it involves the
combined effects of conduction and fluid motion.

Answer 2

convection

Question 3

is the energy
emitted by matter in the form of electromagnetic waves (or photons) as a result of the changes in the electronic configurations of the atoms or molecules.

Answer 3

radiation

Question 4

the form of energy that
can be transferred from one system to another as a result of temperature difference.

Answer 4

heat

Question 5

The science that deals with the determination of the rates of such energy transfers is

Answer 5

heat transfer

Question 6

what law of thermodynamics requires that the rate of
energy transfer into a system be equal to the rate of increase of the energy of
that system

Answer 6

first law or the conservation of energy

Question 7

law of thermodynamics that requires that heat be transferred in the direction
of decreasing temperature

Answer 7

second law or the state of entropy

Question 8

The basic requirement for heat transfer is the presence of a

Answer 8

temperature difference

Question 9

is the driving force for heat
transfer,

Answer 9

temperature difference

Question 10

the temperature difference per unit length or the rate of change of temperature

Answer 10

temperature gradient

Question 11

NOTE

The larger the temperature gradient, the higher
the rate of heat transfer.

Question 12

The heat transfer problems
encountered in practice can be considered in two groups:

Answer 12

(1) rating and
(2) sizing problems.

Question 13

The forms of energy
related to the molecular structure of a system and the degree of the molecular
activity are referred to as the

Answer 13

microscopic energy

Question 14

The sum of all microscopic
forms of energy is called the _________ of a system, and is denoted by
U (or u on a unit mass basis).

Answer 14

internal energy

Question 15

portion of the internal energy of a system associated with the kinetic energy of the molecules is called_______

Answer 15

sensible energy or
sensible heat.

Question 16

The internal energy associated with the phase of
a system is called ______

Answer 16

latent energy or latent heat.

Question 17

The internal energy associated with the atomic bonds in
a molecule is called _______

Answer 17

chemical (or bond) energy

Question 18

the internal energy
associated with the bonds within the nucleus of the atom itself is called _____

Answer 18

nuclear energy.

Question 19

in this equation

h=u +Pv

Pv represents the _______

Answer 19

flow energy of the fluid (also called the flow work)

Question 20

in this equation

h=u +Pv

The internal energy u represents the microscopic energy of a _______

Answer 20

nonflowing fluid

Question 21

in this equation

h=u +Pv

the enthalpy h represents the microscopic energy of a _______.

Answer 21

flowing fluid

Question 22

is defined as the energy required to
raise the temperature of a unit mass of a substance by one degree

Answer 22

specific heat

Question 24

The specific heats of a substance, in general, depend on two independent
properties such as _____

Answer 24

temperature and pressure.

Question 25

ideal gas depend on

Answer 25

temperature only

Question 26

A substance whose specific volume (or density) does not change with temperature or pressure is called an

Answer 26

incompressible substance

Question 27

Work done per unit time is called ____-, and is denoted by W · .

Answer 27

power

Question 28

In daily life, we frequently refer to the sensible and latent forms of internal energy as ______

Answer 28

heat

Question 29

The amount of heat transferred per unit time is called

Answer 29

heat transfer rate

Question 30

The rate of heat transfer per unit area normal to the direction of heat transfer is called

Answer 30

heat flux

Question 31

A large number of engineering devices such as water heaters and car radiators involve mass flow in and out of a system, and are modeled as

Answer 31

control volumes

Question 32

steady means

Answer 32

no change with time

Question 33

The amount of mass flowing through a cross section of a flow device per unit time is called the

Answer 33

mass flow rate

Question 34

h is the slope of the temperature curve on a T-x diagram (the rate of change of T with x), at location x

Answer 34

temperature gradient

Question 35

the rate of heat transfer through a unit thickness of the material per unit area per unit temperature difference.

Answer 35

thermal conductivity

Question 36

is the mode of energy transfer between a solid surface and the adjacent liquid or gas that is in motion, and it involves the combined effects of conduction and fluid motion.

Answer 36

convection

Question 37

Convection is called _______ if the fluid is forced to flow over the surface by external means such as a fan, pump, or the wind

Answer 37

forced convection

Question 38

convection is called_______if the fluid motion is caused by buoyancy forces that are induced by density differences due to the variation of temperature in the fluid

Answer 38

natural (or free) convection

Question 39

the rate of convection heat transfer is also reffered to as

Answer 39

newton's law of cooling

Question 40

is the energy emitted by matter in the form of electromagnetic waves (or photons) as a result of the changes in the electronic configurations of the atoms or molecules.

Answer 40

radiation

Question 41

NOTE Unlike conduction and convection, the transfer of energy by radiation DOES NOT REQUIRE the presence of an intervening medium

Question 42

NOTE Most heat transfer problems encountered in practice are transient in nature, but they are usually analyzed under some presumed steady conditions since steady processes are easier to analyze, and they provide the answers to our questions.