Chapters 1 (THERMODYNAMICS) Flashcards
(332 cards)
1
Q
Enthalpy of an ideal gas is a function only of ________
A
Temperature
2
Q
Which of the following is the most efficient thermodynamic cycle?
A
Carnot
3
Q
What is the first law of thermodynamics?
A
Energy can neither be created nor destroyed
4
Q
An ideal gas is compressed isothermally. What is the enthalpy change?
A
Zero
5
Q
Name the process that has no heat transfer.
A
Adiabatic
6
Q
An ideal gas is compressed in a cylinder so well insulated that there is essentially no heat transfer. The temperature of the gas
A
Increases
7
Q
What is the Sl unit of pressure?
A
Pascal
8
Q
The equation Cp = Cv + R applies to which of the following?
A
Ideal gas
9
Q
In the flow process, neglecting kinetic and potential energies, the integral of Vp represents what ?
A
Shaft work
10
Q
Mechanical energy of pressure transformed into energy of heat.
A
Enthalpy
11
Q
The theory of changing heat into mechanical work.
A
Thermodynamics
12
Q
Average pressure on a surface when a changing pressure condition exist.
A
Mean effective pressure
13
Q
Which of the following cycles consist two isothermal and two constant volume processes?
A
Stirling cycle
14
Q
A control volume refers to what?
A
A fixed region in space
15
Q
In the polytropic process, PV^n = constant, if the value of n is infinitely large, the process is
A
Isometric
16
Q
If the temperature is held constant and the pressure is increased beyond the saturation pressure, then the working medium must be:
A
compressed liquid
17
Q
Is one whose temperature is below the saturation temperature corresponding to its pressure
A
Subcooled liquid
18
Q
Number of molecules in a mole of any substance is a constant is called
A
Avogadro’s number
19
Q
If the pressure of a gas is constant the volume directly proportional to the absolute temperature
A
Charles’ Law
20
Q
The number of protons in the nucleus of an atom or number of electrons in the orbit of an atom
A
Atomic number
21
Q
In a P-T diagram of a pure substance, the curve separating the solid phase from the liquid phase is:
A
Fusion curve
22
Q
A water temperature of 18 °F in the water cooled condenser is equivalent in °C to
A
10
23
Q
The latent heat of vaporization in Joules per kg is equal to
A
22.6 x 10^5
24
Q
Form of energy associated with the kinetic energy of the random motion of large number of molecules
A
Heat
25
If the temperature is held constant and the pressure is increased beyond the saturation pressure, then, the working medium must be:
Compressed liquid
26
Is the condition of pressure and temperature at which a liquid and its vapor are indistinguishable
Critical Point
27
When a substance in gaseous state is below the critical temperature, it is called
Vapor
28
Superheated vapor behaves
Approximately as a gas
29
Which of the following provides the basis for measuring thermodynamic property of temperature?
Zeroth Law of thermodynamics
30
Which of the following is commonly used as liquid absorbent
Ethylene glycol
31
Mechanism designed to lower the temperature of air passing through it.
Air cooler
32
A device for measuring the velocity of wind.
Anemometer
33
Heat normally flowing from high temperature body to a low temperature body wherein it is impossible to convert heat without other effects.
Second law of thermodynamics
34
The temperature at which its vapor pressure is equal to the pressure exerted on the liquid
Boiling point
35
A nozzle is used to
Increase velocity and decrease pressure
36
The sum of the energies of all the molecules in a system where energies appear in several complex form.
Internal energy
37
The total energy in a compressible or incompressible fluid flowing across any section in a pipeline is function of
Flow energy, kinetic energy, height above datum and internal energy
38
The ratio of the density of a substance to the density of some standard substance
Specific gravity
39
Is one whose pressure is higher than a saturation pressure corresponding to its temperature
Compressed liquid
40
The changing of solid directly to vapor without passing through the liquid state is called
Sublimation
41
Weight per unit volume is termed as
Weight density
42
What is the S1 unit of force?
Newton
43
The volume of fluid passing a cross-section of steam in unit time.
Discharge
44
What equation applies in the first law of thermodynamics for an ideal gas in a reversible open steady-state system?
Q + VdP = H2 – H1
45
A pressure of 1 millibar is equivalent to
1000 dynes/cm^2
46
When a system deviates infinitesimally from equilibrium at every instant of its state, it is undergoing:
quasi-static process
47
What is the force which tends to draw a body toward the center about which it is rotating?
Centripetal force
48
What is the process that has no heat transfer?
Adiabatic
49
Which of the engine is used for fighter bombers
Turbojet
50
Exhaust gases from an engine posses:
Kinetic Energy
51
A critical point the latent enthalpy of vaporization is
Zero
52
What is the force which tends to draw a body towards the center about which it is rotating?
Centripetal force
53
When a system deviates and infinitesimally from equilibrium at every instant of its state, it is undergoing
quasi- static process
54
Work done per unit charge when charged is moved from one point to another
Potential at a point
55
How many independent properties are requires to completely fix the equilibrium state of a pure gaseous compound?
2
56
Which of the following relations defines enthalpy?
h = u + pV
57
Which of the following is true for water at a reference temperature where enthalpy is zero?
Internal Energy is negative
58
On what plane is the Mollier diagram plotted?
h-s
59
The compressibility factor z, is used for predicting the behavior of non - ideal gases. How is the compressibility factor defined relative to an ideal gas? ( subscript c refers to critical value )
z= PV/RT
60
How is the quality x of a liquid - vapor mixture defined?
The fraction of the total mass that is saturated vapor
61
What is the expression for heat of vaporization?
hg-hf
62
What is the value of the work done for a closed, reversible, isometric system?
Zero
63
What is the equation for the work done by a constant temperature system?
W = MRT In (V2/V1)
64
What is true about polytropic exponent n for a perfect gas undergoing an isobaric process?
n = 0
65
How does an adiabatic process compare to an isentropic process?
Both: Heat transfer = 0; Isentropic: Reversible
66
During an adiabatic, internally reversible process, what is true about the change in entropy?
It is always zero
67
For an irreversible process, what is true about the change in entropy of the system and surroundings?
ds > 0
68
For which type of process does the equation dQ = Tds hold?
Reversible
69
Which of the following is true for any process?
∆S (Surrounding) + ∆S (system) ≥ 0
70
Which of the following thermodynamics cycle is the most efficient?
Carnot
71
The ideal reversible Carnot cycle involves four basic processes. What type of processes are they?
Two isothermal and two isentropic
72
What is the temperature difference of the cycle if the entropy difference ∆S, and they work done is W?
W / ∆S
73
Which of the following is not an advantage of a superheated, closed Rankine cycle over an open Rankine cycle?
Increased boiler life
74
Which of the following statements regarding Rankine cycle is not true?
In practical terms, the susceptibility of the engine materials to corrosion is not a key limitation on the operating efficiency
75
Which one of the following is standard temperature and pressure (STP)
0 °C and 1 atm pressure
76
A substance is oxidized when which of the following occurs?
it losses electrons
77
Which of the following is not a unit of pressure?
kg / m-s
78
Definition of Joule
Newton meter
79
Which of the following is the basis for Bernoulli’s law for fluid flow?
The principle of conservation of energy
80
Equation of state for a single component can be any of the following except:
A. the ideal gas law
B. any relationship interrelating 3 or more state functions
C. relationship mathematically interrelating
thermodynamic properties of the material
D.A mathematical expression defining a path between states
A mathematical expression defining a path between states
81
The state of a thermodynamic system is always defined by its:
properties
82
In any non quasi-static thermodynamic process, the overall entropy of an isolated system will
increase only
83
Entropy is the measure of :
randomness or disorder
84
Which of the following statements about entropy is
Entropy of a crystal at 0 °F is zero
85
Work or energy can be a function of all of the following except :
force and distance
power and time
force and time
temperature and entropy
force and time
86
Energy changes are represented by all except which one of the following:
dQ / T
87
U + pV is a quantity called :
enthalpy
88
In flow process, neglecting KE and PE changes, JvdP represents which item below?
Shaft work
89
Power may be expressed in units of
Btu / hr
90
Equilibrium condition exist in all except which of the following?
In a steady state flow process
91
In a closed system (with a moving boundary) which of the following represents work done during an isothermal process?
W= P1 V1 ln V2 / V1
92
A substance that exists, or is regarded as existing, as a continuoum characterized by a low resistance to flow and the tendency to assume the shape of its container.
Fluid
93
A substance that is homogeneous in composition and homogeneous and invariable in chemical aggregation.
Pure substance
94
A substance whose state is defined by variable intensive thermodynamic properties.
Simple substance
95
A system in which there is no exchange of matter with the surrounding or mass does not cross its boundaries.
Closed System
96
A system that is completely impervious to its surrounding or neither mass nor energy cross its boundaries.
Isolated system
97
A system in which there is a flow of mass across its boundaries
Open system
98
The properties that are dependent upon the mass of the system and are total values such as total volume and total internal energy.
Extensive properties
99
The properties that are independent of the mass of the system such as temperature, pressure, density and voltage.
Intensive properties
100
The properties for a unit mass and are intensive by definition such as specific volume.
Specific Properties
101
The condition as identified through the properties of the substance, generally defined by particular values of any two independent properties.
State
102
The only base unit with a prefix kilo is
kilogram
103
The force of gravity on the body.
Weight
104
The mass per unit volume of any substance
Density
105
The force of gravity on unit volume is
specific weight
106
The reciprocal of density is
Specific volume
107
Avogadro’s number, a fundamental constant of nature, is the number of molecules in a gram-mole. This constant is
6.02252 x 10^23
108
The ratio of the gas constant to Avogadro’s number is:
Boltzmann’z constant
109
The absolute zero on the Fahrenheit-scale is at
–459.7 °F
110
Absolute temperatures on the Fahrenheit scale are called:
Degrees Rankine
111
The absolute zero on the Celsius scale is at
-273.15 °C
112
What is the absolute temperature in celsius scale?
degrees Kelvine
113
The Fahrenheit scale was introduced by Gabriel Fahrenheit of amstermdam, Holland in what year?
1720
114
The Centigrade scale was introduced by Anders Celsius in what year?
1740
115
The National Bureau of Standards uses, among others, the liquid - vapor equilibrium of Nitrogen at
–196 °C
116
The liquid - vapor equilibrium of Oxygen is at what temperature?
-182.97 °C
117
The solid- liquid equilibrium of Mercury is at what temperature?
-38.87 °C
118
The national Bureau of standards uses, among others, the liquid- vapor equilibrium of hydrogen at
–253 °C
119
The solid- liquid equilibrium of Tin is at what temperature?
231.9 °C
120
The solid-liquid equilibrium of Zinc is at what temperature?
419.505 °C
121
The liquid-vapor equilibrium of sulfur is at what temperature?
444.60 °C
122
The solid-liquid equilibrium of Antimony is at what temperature?
630.5 °C
123
The solid liquid equilibrium of silver is at what temperature?
960.8 °C
124
the solid-liquid equilibrium of Gold is at what temperature?
1063 °C
125
The solid-liquid equilibrium of Platinum is at what temperature?
1774 °C
126
The solid-liquid equilibrium of Tungsten is at what temperature!
3370 °C
127
The device that measures temperature by the electromotive force.
thermocouple
128
The emf is a function of the temperature difference between the junction, a phenomenon called :
Seebeck effect
129
A device that measure temperature by the electromotive force called thermocouple was discovered by :
Seebeck
130
When two bodies, isolated from other environment, are in thermal equilibrium with a third body, the two are in thermal equilibrium with each other.
Zeroth law of thermodynamics
131
The total entropy of pure substances approaches zero as the absolute thermodynamic temperature approaches zero.
Third law of thermodynamics
132
If any one or more properties of a system change, the system is said to have undergone a
process
133
When a certain mass of fluid in a particular state passes through a series of processes and returns to its initial state, it undergoes a :
cycle
134
The term given to the collection of matter under consideration enclosed within a boundary
System
135
The region outside the boundary or the space and matter external to a system
Surrounding
136
The true pressure measured above a perfect vacuum
Absolute pressure
137
The pressure measured from the level of atmospheric pressure by most pressure recording instrument like pressure gage and open ended manometer
Gage pressure
138
The pressure obtained from barometric reading
Atmospheric pressure
139
It is a form of energy associated with the kinetic random motion of large number of molecules
Heat
140
The heat needed to change the temperature of the body without changing its phase
Sensible heat
141
The heat needed by the body to change its phase without changing its temperature
Latent heat
142
The measure of the randomness of the molecules of a substance
Entropy
143
The heat energy transferred to a substance at a constant pressure process is
enthalpy
144
It is the energy stored within the body
Internal energy
145
A theoretically ideal gas which strictly follows Boyle’s law and Charle’s law of gases
Perfect gas
146
In a confined gas, if the absolute temperature is held constant, the volume is inversely proportional to the absolute pressure
Boyle’s Law
147
In a confined gas if the absolute pressure is held constant the volume is directly proportional to the absolute temperature.
Charles law
148
The pressure exerted in a vessel by a mixture of gases is equal to the sum of the pressures that each separate gas would exert if it alone occupied the whole volume of the vessel.
Dalton’s law
149
At equal volume, at the same temperature and pressure conditions, the gases contain the same number of molecules.
Avogadro’s law
150
A process which gives the same states/conditions after the system undergoes a series of processes :
Cyclic process
151
A thermodynamic system that generally serves as a heat source or heat sink for another system.
Heat reservoir
152
A thermodynamic system that operates continuously with only energy (heat and work) crossing its boundaries; its boundaries are impervious to the flow
of mass.
Heat engine
153
A surface that is impervious to heat is
adiabatic surface
154
One of the consequences of Einstein's theory of relativity is that mass may be
converted into energy and energy into mass, the relation being given by the famous equation, E = mc^2. What is the value of the speed of light c?
2.9979 x 10^10 cm/s
155
In the polytropic process we have pv = constant, the value of n is infinitely large, the process is called
constant volume process
156
The thermodynamic cycle used un a thermal power plant is :
Rankine
157
Fo the same heat input and same compression ratio :
efficiency depends mainly on working substance
158
A heat exchange process where un the product of pressure and volume remains constant called :
hyperbolic process
159
Which of the following provides the basis for measuring thermodynamics property of temperature?
Zeroth law of thermodynamics
160
1 watt
1 Nm/s
161
Under ideal conditions, isothermal al, isobaric, isochoric and adiabatic processes are :
quasi-static processes
162
Isentropic flow is
reversible adiabatic flow
163
Exhaust gases from an engine possess
kinetic energy
164
The extension and compression of a helical spring is an example of what process?
reversible process
165
At critical point the latent enthalpy of vaporization is
zero
166
Which of the following relations is not applicable in a free expansion process?
Change in temperature is zero
167
The triple point of a substance is the temperature and pressure at which :
the solid does not melt, the liquid does not boil and the gas does not condense
168
According to Clausius statement :
A. Heat flows from hot substance to cold substance, unaided
B. Heat cannot flow from cold substance to hot substance
C. Heat can flow from cold substance to hot substance with the aid of external work
D. A and C
A and C
169
A heat is supplied heat at rate of 30 000 J/s gives an output of9 kW. The thermal efficiency of the engine is
30%
170
The RMS velocity of hydrogen gas at N.T.P is approximately
1839 m/s
171
"It is impossible to construct a heat engine that operates in a cycle and receives a given quantity of heat from a high temperature body and does an equal amount of work" The above statement is known as :
Kelvin - Planck’s law
172
For steam nozzle, which of the following ratios will have the value less than unity?
Specific volume at inlet / (Specific volume outlet)
173
A Bell- Coleman cycle is a reversed
Joule cycle
174
Ericsson cycle consists of the following processes:
two isothermal and two constant pressure
175
A steam nozzle changes
heat energy into kinetic energy
176
Which is not correct for calculating air standard efficiency?
Gases dissociate at higher temperatures
177
According to Pettlier Thomson effect:
Work can’t be converted to heat
178
In actual gases the molecular collisions are:
inelastic
179
The Beattie-Bridgeman equation of state is quite accurate in cases of:
densities less than about 0.8 times the critical density
180
Which of the following statement about Vander Waals equation is correct?
It has three roots of identical value at the critical point
181
The Clayperon’s equation is applicable to :
a change of state when two phases are in equilibrium
182
The vapor pressure is related to the enthalpy of vaporization by the:
Clausius-Claypeyron’s ewuation
183
Solubility of a gas in a liquid at small concentration can be represented by which law?
Henry’s law
184
A compound pressure gauge is used for to measure:
positive and negative pressures
185
Which of the engine is used for fighter bombers?
Turbojet
186
The thermal efficiency of gas-vapor cycle as compared to steam turbine or gas turbine
greater than
187
The process in which heat energy is transferred to thermal energy storage device is known as:
regeneration
188
The absolute zero in Celsius scale is:
-273
189
What is the temperature when water and vapor are in equilibrium with the atmospheric pressure?
Steam point
190
The temperature of a pure substance at a temperature of absolute zero is:
zero
191
When the number of reheat stages in a reheat cycle is increased, the average temperature :
increases
192
The temperature measurement in an ordinary thermometer which has constant specific humidity.
Dew point temperature
193
In a closed vessel, when vaporization takes place, the temperature rises. Due to the rising temperature, the pressure increases until an equilibrium is established between the temperature and pressure. The temperature of equilibrium is called :
Boiling point
194
When hot soup was served in a cup during dinner an engineer was so eager to drink it. Since it was hot, he added cubes of ice to cool the soup and stirred it. He noticed that dew starts to form on the outermost surface of the cup. What is this temperature equal to?
equal to air’s dew point temperature
195
Is a measure of the energy that is no longer available to perform useful work within the current environment
Absolute entropy
196
A graph of enthalpy versus entropy for steam
Mollier diagram
197
The reaction of inertia in an accelerated body is called
Kinetic reaction
198
A Mollier chart of thermodynamic properties is shown in which of the following diagrams?
h-S diagram
199
The following are included in the first law thermodynamics for closed system EXCEPT :
Internal energy
200
All processes below are irreversible except one. Which one?
Elastic tension and release of a steel bar
201
The combination of conditions that best describes thermodynamics process is given by which of the following?
Has successive states through which the system passes
202
The sum of the energies of all the molecules in a system where energies appear in several complex forms is the:
internal energy
203
The Carnot refrigeration cycle includes all of the following process except:
isenthalpic expansion
204
The maximum possible work that can be obtained cycle operating between two reservoirs is found from
Carnot efficiency
205
The following factors are necessary to define thermodynamic cycle except
the time it takes to complete the cycle
206
All of the following terms included in the second for open system except
Average work
207
The following terms are included in the first law of thermodynamics for open systems except
magnetic system
208
The following terms are included in the first law of thermodynamics for closed systems except:
kinetic energy
209
Which of the following statements about a path function is not true?
It represents values of p,v,t and s between states that are path functions
210
A constant pressure thermodynamic process obeys:
Charles Law
211
The first and second laws of thermodynamics are:
energy equations
212
Represents the temperature an ideal gas will attain when it is brought to rest adiabatically
Stagnation temperature
213
Gauge pressure and absolute pressure differ from each other by:
atmospheric pressure
214
Each of the following are correct values of standard atmospheric pressure except:
1013mm Hg
215
All of the following are properties of an ideal gas except:
Viscosity
216
Which of the following is not the universal gas constant?
8314 J/mol.K
217
The following are all commonly quoted values of standard temperatures and pressure except:
0 °F and 29.92 in Hg
218
The variation of pressure in an isobaric process is
zero
219
For fluid flow, the enthalpy is the sum of internal energy and
work flow
220
A thermodynamic process whose deviation from equilibrium is infinitesimal at all time is
in quasi-equilibrium
221
Which thermodynamic property best describes the molecular activity of a substance
Internal energy
222
Stagnation enthalpy represents the enthalpy of fluid when it is brought to rest
adiabatically
223
During stagnation process, the kinetic energy of a fluid is converted to enthalpy which results in an:
increase in the fluid temperature and pressure
224
The properties of fluid at the stagnation in state are called
stagnation state
225
All of the following are thermodynamic properties except
modulus of elasticity
226
A liquid boils when its vapor pressure equals
the ambient pressure
227
A system composed of ice and water at 0 °C is said to be:
A. a multiple material
B. in thermodynamic equilibrium
C. in thermal equilibrium
All of the above
228
The heat of fusion of a pure substance is:
the energy required to melt the substance
229
The heat of vaporization involves the change in enthalpy due to :
the change in phase from liquid to gas
230
The heat of sublimation involves the change in enthalpy due to :
the change in phase from solid to gas
231
A specific property
defines a specific variable ( e.g temperature)
232
A material's specific heat can be defined as :
all of the above
233
If a substance temperature is less than its saturation temperature, the substance is :
Subcooled liquid
234
If a substance temperature is equal to its saturation temperature, the substance is
saturated liquid and vapor
235
If a substance’s temperature is greater than saturation temperature, the substance is a
superheated vapor
236
Critical properties refer to
property values where liquid and gas phase are indistinguishable
237
For the saturated vapor, the relationship between temperature and pressure is given by:
the steam table
238
Properties of a superheated vapor are given by
a superheated table
239
Properties of non-reacting gas mixtures are given by
volumetric weighting for molecular weight and density and geometric weighting for all other properties except entropy
240
The relationship between the total volume of a mixture of non- reacting gases and their partial volume is given by
Amagat’s law
241
The relationship between the total pressure of a mixture of non reacting gases and the partial pressures of constituents is given by
Dalton’s law
242
Which of the following is the best definition of enthalpy?
The amount of useful energy in a system
243
Which of the following statements is not true for real gases?
Real gases are found only rarely in nature
244
The stagnation state is called the isentropic stagnation state when the stagnation process is:
reversible as well as adiabatic
245
The entropy of a fluid remains constant during what process?
isentropic stagnation process
246
All of the following processes are irreversible except
an isentropic deceleration of a moving perfect fluid
247
All of the following processes are irreversible except:
an isentropic compression of a perfect gas
248
All of the following processes are irreversible except
elastic tension and release of a steel bar
249
Which of the following state(s) is/are necessary for a system to be in thermodynamic equilibrium?
Chemical, mechanical, and thermal equilibrium
250
Adiabatic heat transfer within a vapor cycle refers to:
The transfer of energy from one steam to another in a heat exchanger so that the energy of the output streams
251
Which of the following gives polytropic under n?
A = log P2/P1 / log V1/V2
252
The work done in an adiabatic process in a system?
is equal to the change in total energy of a closed system plus net heat transfer
253
Based on the first law of thermodynamics, which of the following is wrong?
The heat transfer cannot exceed the work done
254
Assuming real processed, the net entropy change in the universe:
is positive
255
Which of the following types of flowmeters is most accurate?
Pitot tube
256
What if referred by control volume?
Fixed region in space
257
What is the most efficient thermodynamic cycle?
Carnot
258
How do you treat a statement that is considered a scientific law?
Accept aa a summary of experimental observation
259
An instrument commonly used in most research and engineering laboratories because it is small and fast among the other thermometers
Thermocouple
260
In an actual gases, the molecular collisions are
inelastic
261
Which of the following is used in thermal power plant?
Rankine
262
The elongation and compression of a helical spring is an example of
reversible process
263
Otto cycle consists of
Two isentropic and two constant volume processes
264
Brayton cycle has
Two isentropic and two constant pressure processes
265
A bell- Coleman cycle is a reversee
Joule cycle
266
A steam nozzle changes
heat energy into kinetic energy
267
The pilot tube is a device used for measurement of
velocity
268
The continuity equation is applicable to
Conservation of mass
269
The work done by force of R Newtons moving in a distance of L meters is converted entirely into kinetic energy and expressed by the equation:
RL= 1/2 MV^2
270
Gas being heated at constant volume is undergoing the process of:
isometric
271
Dew point is defined as
The temperature to which the air must be cooled constant pressure to produce saturation
272
What do you call the changing of an atom of element with a different atomic mass?
Atomic transmutation
273
What do you call the weight of the column of air above the earth’s surface?
Atmospheric pressure
274
What keeps the moisture from passing through the system?
Dehydrator
275
What condition exists in an adiabatic throttling process?
Enthalpy is constant
276
The specific gravity of a substance is a ratio of its density to the density of:
water
277
A compound pressure gauge is used to measure:
positive and negative pressures
278
Isentropic flow is
reversible adiabatic flow
279
Under ideal conditions, isothermal, isobaric, isochoric and adiabatic processes are:
quasi-static processes
280
One watt is
1 N.m/s
281
A temperature above which a given gas cannot be liquefied
Critical temperature
282
The effectiveness of a body as a thermal radiator at a given temperature
Emissivity
283
Which if the following occurs in a reversible polytropic process?
Some heat transfer occurs
284
The instrument used to measure atmospheric pressure is
Barometer
285
A pneumatic tool is generally powered by
air
286
Which of the following gases can be used to measure the lowest temperature?
Helium
287
The triple point of a substance is the temperature and pressure at which:
The solid does not melt, the liquid does not boil and the gas does not condense
288
Which of the following relations is not applicable in a free expansion process?
Change in temperature is zero
289
Ericsson cycle has
Two isothermal and two constant pressure processes
290
A stirling cycle has
Two isothermal and two constant volume processes
291
The temperature of the fluid flowing under pressure through a pipe is usually measured by;
A. a glass thermometer
B. an electric resistance thermometer
C. a thermocouple
all of the above
292
Specific heat capacity in an SI derived unit described as
kJ/ kgK
293
Which of the following is mathematically thermodynamics property?
A point function
294
When the expansion or compression of gas takes place “without transfer of heat” to or from the gas, the process is called:
adiabatic
295
Another name for the liquid valve is:
King valve
296
A liquid whose temperature is lower than the saturation temperature corresponding to the existing pressure
Subcooled liquid
297
The law that states “Entropy of all perfect crystalline solids is zero at absolute zero temperature
Third law of thermodynamics
298
What should be the temperature of both water and steam whenever they are present together?
Saturation temperature for the existing pressure
299
A manometer is an instrument that is used to measure:
air pressure
300
What is the area under the curve of a temperature entropy diagram?
Heat
301
What do bodies at temperature above absolute zero emit?
Thermal radiation
302
In the absence of any irreversibilities, a thermo electric generator, a device that incorporates both thermal and electric effects, will have efficiency of a/an
Carnot cycle
303
Both Stirling and Ericson engines are
external combustion engines
304
Nozzles does not involve any work interaction. The fluid through this device experiences
no change in potential energy
305
If the actual kinetic energy of a nozzle is Ka and Ki is the maximum value that can be attained by an isentropic expansion from an initial to final state, then the efficiency of the nozzle is:
Ka / Ki
306
The convergent section of a nozzle increases the velocity of the flow of the gas. What does it to do on its pressure?
It decreases the pressure
307
In a closed vessel, when vaporization takes place, the temperature rises. Due to the rising temperature, the pressure increases until an equilibrium is established between the temperature and pressure. The temperature of equilibrium is called
boiling point
308
At steam point, the temperatures of water and its vapor at standard pressure are:
in equilibrium
309
When hot soup was served in a cup during dinner, an engineer was so eager to drink it. Since it was hot, he added cubes of ice to cool the soup and stirred it. He noticed that dew starts to form on the outermost suriace of the cup. He wanted to check the temperature of the outermost surface of the cup. What is this temperature equal to?
Equal to air's dew point temperature
310
What do you call a conversion technology that yields electricity straight from sunlight without the aid of a Working substance like gas or steam without the use of any mechanical cycle?
Photovoltaic-energy conversion
311
Which of the following property of liquid extend resistance to angular or shear deformation
Viscosity
312
What is the pressure at the exit of a draft tube in a turbine
Atmospheric
313
When changes in kinetic energy of a compressed gas are negligible or insignificant, the work input to an adiabatic compressor is
equal to change in enthalpy
314
What is the area under the curve of a pressure volume diagram
Nonflow work
315
In Stirling and Ericson cycle, regeneration can
increase efficiency
316
The first law of thermodynamics is based on which of the following principles?
Conservation of energy
317
In a two-phase system, 30% moisture means
70% vapor, 30% liquid
318
At 101.325 kPa, the boiling point of water is 100 C, If the pressure is decreased the boiling temperature will:
decrease
319
Which of the following is equivalent to 1Hp in Btu/hr?
2545
320
What is the pressure above zero?
Gage pressure
321
One Newton -meter is equal to:
1 Joule
322
Which of the following is the instrument used to measure fluid velocity?
Pitot tube
323
Cryogenic temperature ranges from:
-250 ° F to -459 °F
324
Steam at 2kPa is saturated at 17.5 °. In what state will the state be at 40 °C if the pressure is 2.0 kPa?
Superheated
325
Acceleration is proportional to force
Newtons law
326
Which of the following could be defined a simply push and pull?
Force
327
The true pressure measured above a perfect vacuum is:
absolute pressure
328
If an initial volume of an ideal gas is compressed to one -half its original volume and to twice its original temperature, the pressure:
quadruples
329
When the expansion or compression of gas takes place without transfer of heat to or from the gas, the process is called:
adiabatic process
330
The body radiates heat proportional to the fourth power of its absolute temperature
Stefan-Boltzmann law
331
All substances emit radiation, the quantity and quality of which depends upon the absolute temperature and the properties of material, composing the radiating body.
Planck’s law
332
For bodies in thermal equilibrium with their environment, the ratio of total emissive power to the absorptivity is constant at any temperature
Kirchhoff’s law
