Download Prime thermodynamics 12.3 and more Study notes Thermodynamics in PDF only on Docsity!
PRIMEREVIEW ONLINE
MECHANICAL ENGINEERING REVIEW
POWER &INDUSTRIALPLANT ENGINEERING
PRIME'S SUPPLEMENTARY ENHANCERS (THERMODYNAMICS 03)
THERMODYNAMICS 03 PSEMODULE 12.3 (SOLUTION)
P mAh= m(h,- h,) where: h,= xh,+ h, h, = 152 +0.88 (2415)kJkg = 2277.2 kJkg I. Steam at a pressure of9 har (h = 743 kJkg. hg = 2031 kJ/kg) is generated
in an exhaust gas boiler fom feedwater at 80°C (h = 334,9 kJkg). If the
dryness fraction of the steam is 0.96. determine the heat transfer per kilogram of steam. A. 2357.
r-0231n-2m2-209951w
C. 1357.86 Ans.B
B.3357.86 D. 5357.
7 Which of the following is the basis for Bernoulli's law for fluid flow?
Solution
A. The principle of conservation of mass
Q Ah =h,- h, B.
whereh, = , +sh, = 743+(0.96)(2031)kJAg = 2692.76 kJg
h, 334.9 kJkg given
Q 2692.76-334.9 kJkg = 2357.86 kJkg
Ans.
The principle of conservation of energy
C. The continuity equation
D. Fourier's law
Answer:B
8. Steam enters the superheaters of a boiler at a pressure of 20 bar (hr= 909
kJkg. hrg= 1890 kJkg. Vg#0.09957 mkg ) and dryness 0.98 and leaves
at the same pressure at a temperature of 350°C ( h = 3138 kJkg. v =0. 1386 m/kg ). Find the percentage increase in volume due to drying and
superheating
A. 12.
If wet saturated steam at 8 bar (hfg = 2048 kJ/kg) requires 82 kJ of heat per kg of steam to completely dry it, what is the dryness fraction of the steam? A..0.76 C. 0. C. 32. B.0.86 D. 0.66 (^) B.22.04 D. 42. Selution: (^) Selulion:
TTU7E
Ans. D
Q+xh,=h (^) 9%U 0.1386 -0.98(0.09957))42.04%
Q 2048-B0.96 0.98 (0.09957)
AnsC
- Steam at the rate of 500 kg/hr is produced by a steady flow system boiler
from feedwater entering at 40°C. Find the rate at which heat is
transformed in kCalhr if^ the^ enthalpy^ of^ steam is^600 kCalkg^ and of steam 50 kCakg. A. 275,000kCal/hr
B. 175,000 kCal/hr
3. How many independent properties are required to completely fix the
equilibrium stale of a pure gaseous compound? A
C. 375,000 kCal/hr
D. 475,000 kCalhr D.
Solutions
Answer: B
Qm(Ah)
4. If wet saturated steam at 8 bar (hty 2048 kJ/kg) requires 82 kJ of heat
per kg of steam to completely dry it, what is the drynessOdfraction of the Q275 000
steam?
A. 0.07 (^) C.0.96 (^) Ans.A B. 0.86 D. 0.
- Steam leaves an industrial boiler at 827.4 kPa and 171.6°C (hs = 727. kg. hi 2043.2^ kJ/kg).^ A^ portion^ of the steam is^ passed^ through^ a
throttling calorimeter and is exhausted to the atmosphere when the
calorimeter pressure is 1014 kPa and a temperature of 115.6°C (h =
2707.6 kJkg). How much moisture does the steam leaving the boiler
contain?
Solion:
Q+ kh h
h (^2048 82) =0.96 y 1-0.96 0.04 4%
x=
Ans. D
A. 2.08 %
B. 3.08 %
C. 4.08 %
D. 5.08 %
Salkan: Which of the following is tnue for water at a reference temperature
where enthalpy is zero?
Internal energy is negative B.
h h+xh
2707.6 727.25 +x (2043.2)
0.969 thus. y= 1-x=0.
Alternale Sol (Mode Stat )/ Mode 3.
A. Entropy is non zero
Specific volume is zero
D
C
Vapor pressure is zero Answer: A 100 727.
- A turbo-generator is supplied with superheated steam at a pressure of 30
bar and temperature 350°c (h = 3117 kJkg). The pressure of the exhaust
steam from the turbine is 0.06 bar (^) (hr =^152 kJ/kg, hiy =^2415 kJ/kg) (^) with a dryness fraction of 0.88. If the turbine uses 0.25 kg per second, calculate the power equivalent of the total enthalpy drop. A. 109.95 kW
2707.6 x 3.08%
AusB
- One kilogram of wet steam at a pressure of 8 bar ((Vg = 0.2404 m /kg. v
0.0011148 m°*g ) and dryness 0:94 is expanded until the pressure is 4
bar (= 04625 m kg, = 0.0010836 m°kg ). If expansion follows the
law PVC, where n = 1.12, find the dryness fraction of the steam at the lower pressure A. 0.
C. 309.95 kW B. 209.95 kW D. 409.95 kW Soliion: C. 0.
B. 0.4197 D. 0.
PRIME REVIEW ONLINE
MECHANICAL ENGINEERING REVIEW
POWER&INDUSTRIAL PLANT ENGINEERING PRIMES (^) SUPPLEMENTARY (^) ENHANCERS (THERMODYNAMICS 03)
1S. Wet saturated steam at 16 bar (hr = 859 kJkg. hr = 1935 kJkg. x = 0.98) reducing valve and is throttled to a pressure of 8 bar ( hr = 721 kJkg. hr
2048 kJ/kg). Find the dryness fraction of the reduced pressure steam.
A.0.
Sallion
y0.226 m' /kg
C.0.
B. 0.7733 D. 0.
then, P, V= P,V Solution
(8)(0.226) =(4)(»," h, =h, where: h =h,+ xh, ht, hht, h
859+(0.98)(1935) 721 +x, (2048)
u,= 04197 m'/kg
0.4197 = 0.0010836 + x, (0.4625 -0.0010836)) x,^ =^ 0. X= 0.9073 (^) Ans. C Alternate Sol: Caku: Mode 3 2
) 0 0.
16. Identify the condition of "steam" at the following pressure and
temperature 1150 psia. 300°F (Use: Steam Table, English Unit)
A. compressed liquid
B. indeterminate- may be saturated liquid
C. indeterminate wet -vapor or saturated vapor.
D. superheated
94 y 0.226 m' /ke y
PV=P,V;
-1150p Solution: sa (s(0.226)= (4)(V.)* (^150) psia and 300°F
V,=0.
1150 psia =56l.9°F 562°F
since. therefore; it is a Compressed liquid
Ans. A
mode 3 2
- How does an adiabatic process compare to an isentropic process?
A. Adiabatic: Heat transfer 0, Isentropic: Heat transfer =
B. Adiabatic: Heat transfer = 0. Isentropic: Heat transfer = 0 Adiabatic: Reversible, Isentropic: Not reversible
D. Both: Heat transfer =0; Isentropic: Reversible
Answer: D
0.4197 x 90.73%
Ans. A
- How is the (^) quality x of a (^) liquid- (^) vapor mixture defined?
A. The fraction of the total volume that is saturated vapor
B. The fraction of the total volumethat is saturated liquid
C. The fraction of the total mass (^) that is saturated vapor
D. The fraction of the total mass thatl is saturated liquid
18. Which of the following is true for any process?
A AS (Surrounding) AS (system)>
B. AS Surrounding) + AS(system) <
AS(Surrounding)+ AS (system) D.AS(Surounding) AS(system) 2 0
Answer: C
13. A 2.5 liters of superheated steam at 25 barand 400°C(v=0.1252 m'/kg
is expanded in an engine to a pressure of 0.1 bar (V=14.674 m'kg
= 0.0010102 m kg) when its dryness fruction is 0.9. Find the final
volume of the steam.
Answer: DD
19. A vessel of volume 8.7 m contains air and dry saturated steam at a total
pressure of 0.06 bar and temperature 29°C (Pia = 0.04 bar, v = 34. m kg). Taking R for air as 287 Jkg-K, calculate the mass of steam and the mass of air in the vessel.
A 0.25 kg. 0.204 kg
B. 0.35 kg. 0.204 kg
C. 363.74 liters
D. 463.74 liters
A. 163.74 liters B. 263.74 liters
Salukion
Im 0.01997 kg
C.0.25 kg. 350 kg
2.5 L D.0.35 kg. 045 kg
0.1252 m/kg100OL
U=+xu, =0.0010102 +0.9 (14.674 0.0010102)
U= 13.207 m
then: V =mv (0.01997)(13.207)(1000)
V 263.71L Ans. B
- A 1.5 kg of wet steam at a pressure of 5 bar (hr= 640 kJkg. hy = 2109 kJ/kg) dryness 0.95 is blown into 70 liters of water of 12°C (h = 50.
kJ/kg). Find the final enthalpy of the mixture
A. 74.80 kJ/kg
olihon
8.7m 0.25 kg 34.80 m' /kg 0.02 (^) bar (100 (^) kPabar )(8.7m)0201 k 0.287 kJkg.K)(29+273) K
Ans. A
- Which of the following is not an advantage of a superheated, closed Rankine cycle over an open Rankine cycle? . Lower equipment cost
B. Increased efficieney
C. Increased turbine life
D. Increased boiler life
C. 94.80 kJkg
B. 84.80 kJ/kg D. 104.80 kJkg
Sluion
=h,+h,
h, = h, +x h, = 640 +0.95 (2109)=2643.55 kJkg
then; m,= (1 kg/L.)(70 L)= 70 kg
Auswer: D
thus: H= m,h,+ m,h, = (^) (1.5)(2643.55) +70(50.4) =^ 7493.325 (^) k
7493.325 kJ t
1.5+ 70 kg
Ans.D
PRIME REVIEW ONLINE POWER^ &^ INDUSTRIAL^ PLANT^ ENGINEERING MECHANICAL ENGINEERING REVIEW PRIME'S SUPPLEMENTARY ENHANCER5 (THERMODYNAMICS 03)
- The National Burcau ofStandards uses, among others, the liquid vapor Salion equilibrium of Nitrogen at A. - 196 °C
P m (h,-h,)-Q AtP - 2 mPa 1, = 350°c B. 196 °C
C. 253 c h,^ 3137.
D. -253 °C (^) At P, 0.ImPa, x = 100% Answer: A
h 2674.9496 k
- A 5 m vessel initially contains 50 kg of liquid water and saturated water P=^ 103137.6412-2674.9496-10kw
vapor at a total intermal energy of 27,300 kJ. Calculate the heat
requirement to vaporize all of the liquid.
A 100,000 kJ
kg
P 46169 kW
Ans.C C. 300,000 kJ B 200,000 kJ (^) D 400,000 kJ
- The solid - liquid equilibrium of Tin is at what temperature?
A. -38.87 °C
38.87 °C
231.9 °C
D. -231.9 °C
Soldion
Q=V, - V,
where V,=27300 kJ
B.
C.
A p 2.
Sm Answer: C
V, 0.10m'/kg
50kg
At V, =0.10m /kg. u, 2600
kg
37. An isobaric steam generating process starts with saturated liquid at 143
kPa. The change in entropy is equal to the initial entropy. What is the
change in^ enthalpy^ during^ the^ process?^ (Hint:^ Not^ all^ of^ the^ liquid^ is
vaporized. ) A 110 kJkg
B. 270 kJkg
Q= mAu = (50ke) 2600-27300 k
Q102700 k Ans. A
C 410 kJ/kg
D 540 kJ/kg
- A 5 kmol of (^) water vapor at (^100) °C and I (^) atmosphere pressure are
compressed isobarically to fonm liquid at 100°C. The process is reversible
and the (^) ideal gas apply. (^) Determine the heat for (^) condensation, Q. for the amount of water given. The heat of vaporization is 2257 kJAg. A. 200 M
eP143kPa (s, 14178 & h, =461.0325)
then: s+as 2s
C. 200 kJ
kg-k
B. 140 MJ D. 410 MJ
Seluiion: Calcu: Mode Stat (Mode 32) x(e)y(h)
f 14178 461.
7.2389 2690.
Q=mh
where m= nMW
-(6 228
Q 203.13 MI h,
Ans.A 2.8356^ yh, =1004.
33. The Clapeyron's equation is applicable to
A 1system in equilibrium
B. a change ofstate
C. a change of state when two phases are in equilibrium
D. a change of state when water and water vapor are invalved
then: Ah h,-h Ah 1004.156 461.0325 543.12 kJkg
Ans. D
38. The National Bureau of Standards uses, among others, the liquid- vapor
equilibrium of hydrogen at
A. -196 C
Answer: C
- The vapor pressure is related to the enthalpy of vaporization by the : A. Clausius Claypeyron's equalion
B. Dalton's law
C. Raoult's law
D. Maxwell's equation
196 °C
C. 253 °C
D. -253 C
B.
Answer: Answer: A
35. Steam flows into a turbine at a rate of 10 kg/s., and 10 kilowatts of heat
are lost from the turbine. Ignoring elevation and kinetic energy effects,
calculate the power output from the turbine.
39. The properties that are dependenl upon the mass of the system and are
total vaues such as total volume and total internal energy. A. Intensive properes
B. Exiensive properties
Specific properties D. State properties inlet conditions exit conditions Answer: B Pressure 2.0^ MPa^ 0.I^ Mpa
Temperature^350 C
Quality 1o0 %^ 40. The Centigrade scale was introduced by Anders Celsius in what year?
A 4000 kW
A. C. 4600 kw B. 1740
C. 1730
D. 1720
B 4400 kW D. 5000 kW
Answer: B
PRIME REVIEW ONLINE MECHANICAL ENGINEERING REVIEW
POWER& INDUSTRIAL PLANT ENGINEERING
PRIME'S SUPPLEMENTARY ENHANCERS (THERMODYNAMICS 03)
- The solid - liquid equilibrium of Zinc is at what temperature? (^) 46. In any non quasi-static thermodynamic process, the overall entropy of an isolated system will. A. increase and then decrease
A. 231.9C
B. 419.505 °C
B. decrease and then increase
C. 444.60 °C
C. increase only D. decrease only
D. 630.5 °C
Answer: B (^) Answer: C
- The solid - liquid equilibnum of Tungsten is at what tempemture? A. 3730 °C B. 3370 °C C. 3073 °C
- Which of the following statements about entropy is false? A. Entropy of a mixture is greater than that of its components under the same condition D. 3037 °C (^) B. An ireversible process increases entropy of the universe C. Net entropy change in any closed cycle is zero Answer: B D. Entropy of a crystal at 0 °F is zero
- An isobaric steam generating process starts with saturated liquid at 143 Answer:^ D kPa. The change in entropy is equal to the initial entropy. What is the change in enthalpy during the process? (Hint: Not all of the liquid is
vaporized.)
A. 10 kJg
B 270 kJkg
48. Equilibri um condition exist in all except which of the following?
A. In reversible processes B. In processes where driving forces are infinitesimals C. In a steady state flow process
D. Where nothing can occur without an effect on the system's
surrounding
Answer: C
C. 410 kJg
D. 540 kJkg*
Selution:
A 0.68 mPa and 170°C: ( h, = 2777 kJkg.u 2582.9 kJtg
&u 285 x 10 m/kg)
At 4 mPa and 370°C: (h, = 3141,7 kJAg. u, = 2864.6 kJkg
- The liquid - vapor equilibrium of Oxygen is at what temperature? A.197.82 °C B. -197.82 °C
C. 18297 C
& 0.06929 m'/kg)
m+m,m A, m D. -182.97 °C
0.03m 0.285 mkg 0.06929 m'/kg
0.03 m Answer:^ D
m0.538 kg
then: (^) 50. The solid - liquid equilibrium of Mercury is at what temperature?
0.06 in0.1115 m'/kg m 0.538 kg
V 38.87 °C
A B. -38.87°C C. 37.88 °C
u+ u mA +m,u muc D. -37.88 °C
285(2582.9)+ 2864.6)= (0.538)n Answer: B
h 2810.69 kikg
H+H,=H
HOHd
S1. The solid - liquid equilibrium of silver is at what temperature?
nb+mh,= mhe A.^ 630.5^ °C
B. 960.8 °C
0.285 o0692(3141.7)=(0.538)h C.^ 1063 °C
h 3071.66 kJkg
ddCE
D. 1774 °C
he u+ PVE Answer:^ B
3071.66 2810.69+P (0.1115)
Pe2340.54 kPa = 2.34 MPa 52.The solid liquid equilibrium of Gold is at what temperalure?
Ans C
A. 630.5 °C
B. 960.8 °C
C. 1063 °C
D. 1774 °C
- Which of the following statements regarding Rankine cycle is not true? A. Use of a condensable vapor in the cycle increases the efficiency of Answer:^ C the cycle B. The temperatures at which energy is transferred to and from the working liquid are less separated than in a Camot cycle C. Superheating increases the efficiency of a Rankine cycle D. In practical terms, the susceptibility of the engine materials to corosion is not a key limitation on the operating efficiency
53. The solid - liquid equilibrium of Platinum is at whal temperature?
A. 630.5 °C
B. 960.8 °
C. 1063 C
D. 1774 C
Answer: D (^) Answer: D
- Equation of state for a single component can be any of the following
except
A. the ideal gas law B. any relationship interelating 3 or more state functions C. relationship matthematically interrelatingthermodynamic properties of the material D. A mathematical expression defining a path between states
- The emf is a function of the temperature difference between the junction, a phenomenon called: A. Seebeck effect B. Stagnation effect C. Primming D. Electromotive force
Answer: D Answer:^ A
POWER & INDUSTRIAL PLANT ENGINEERING
PRIME'S (^) SUPPLEMENTARY ENHANCERS (^) (THERMODYNAMICS 03)
PRIME EVIEV
MECHANICAL ENGINEERING REVIEW
LINE
72. Which of the following is the best definition of enthalpy?
A. The ratio of heat added to the temperature increses in a system B. The amount of useful energy in a system C. The amount of energy no longer available to the system D. The heat required to cause a complete conversion between iwo phases at a constant temperature
- All of the following processes are irreversible except: A. magnetization with hysteresis
B. elastic tension and release of a steel bar
C. inelastic deformation D. heat conduction
Answer: B
Answer: B
- Which of the following state(s) is/are necessary for a system to be in thermodynamic equilibrium?
A. Chemical equilibrium
B. Thermal equilibrium
C. Mechanical equilibrium
D. Chemical, mechanical, and thermal equilibrium
- A vessel with a volume of l m' contains liquid water and water vapor in
cquilibrium at 600 kPa. The liquid water has a mass of I kg. Calculate
the mass of the water vapor. Properties of liquid water and water vapor at 600 kPa : Vr = 0. m kg. Vs = 0.3157 m ^g A. 1.57 kg B. 1.89 kg
Answer: DD
C. 2.54 kg
D. 3.16 kg 82.^ Find^ the^ enthalpy^ of^1 kg^ of^ wet^ saturated^ steam^ at a^ pressure^ of^ 0.20^ bar and dryness^ fraction of 0.85.^ At^ 0.20^ bar.^ hf^
= 251 kJkg. hfg = 2358
kJ/kg
A. 2200 kJ/g
B. 2525.30 kJkg
Selutions
Vtotal= mV+ m,V, = (^) (1)%0.001 101) + (^) me (^) (0.3157) m = 3.16 kg
C. 2255.30 kJkg
D. 2000 kJkg
Seion:
Ans. D (^) h h + Xxhrg=251+0.85( 2358) =2255.30 kJkg
74. Which of the following statements is not true for real gases?
A.
Molecules occupy
a volume not
negligible in^ comparison^ to^ the total volume of gas B. Real (^) gases are (^) subjected to (^) attractive forces between molecules
(e g., Van der Waal'sforces)
C. The law of (^) corresponding states (^) may be used for real gases D. Real gases are found only rarely in nature
Ans. B
83. The liquid-vaporequilibrium of Sulfur is at what temperature?
A 231.9C
B. 419.505 C
C 444.60 °C
Answer: D D.^ 630.5^ PC
Answer:C
- The stagnation state is called the isentropic stagnation state when the
stagnation process is
A. reversible as well dynamic B. isotropic C. adiabatic
- The solid liquid equilibrium of^ Antimony^ is^ at^ what^ temperature^? 630.5C B. 419.505 °C 444.60 C D. 231.9C D. reversible as well as adiabaic
Answer: D o Answer
76. The entropy of a fluid remains constant during what process
A. polytropic stagnation process B. (^) unsteady (^) stagnation process
C. combustion proces
D. isentropic stagnation process
- Find the heat transfer Tequired to coavert 5 kg of water at a pressure of 20 bar and temperature of 21°C^ into steam^ of^ dryness^ fraction^ O.90^ at^ the
sarme presSure.
Properties of Steam: P 20 bar: be=909 kiikg: hg 1890 kJkg
Note: for wauer at21°C. h 88 kIkg
A, 10 610 k
Bll 610kJ
C. 12 610
D. 15 610k
Answer: D
77. If the specific enthalpy of wet saturated steam at a pressure of11 bar is
2681 Kikg. find its dryness fraction. At 11 bar, hr = 781 kJAg & hg
2000 kJkg
A
B..0.
Seldior
C. 0.
D. 0.
h2 (he + xhrg)
h 909+0.9001890)= 2610 kJkg
Qmah =mh-h) 5( 2610 88) 12610 kJ
Seltion
Ans. C h hr + xhss 2681 = 781 + x (2000) X = 0.95 86.^ According^ to^ Petttier^ Thomson^ effect: A. Itis 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 B. It is impossible to construct a device that operates in a cycle and produces no effect other than the transfer of heat from a cooler
body to hotter body
C. When two dissimilar metals are heated at one end and cooled at
other, e.m.f. that is developed is proportional to difference of temperatures at two ends
D. Work can't be converted into heat
AnsC
78. All of the following processes are irreversible exeept
A. stiring of a viscous fluid
B. an isentropic deceleration of a moving perfect fuid
C. an unrestrained expansion of a gas D. phase changes Answer: B
- All of the following processes are irreversible excep. Answer:^ D A. chemical reactions
B. diffusion
C. curent fMow through an electrical resistance
D. an isentropic compression of a perfect gas Answer: D
OWER & TNDUSTRIAL PLANT (^) ENGINEERING PRIME'S SUPPLEMENTARY ENHANCERS (^) (THERMO0TNAMICS (^03)
LINE MECNANICAL ENGINEERING REVIEW
87 Steam at 1000 b/ft pressure and 00°R has specific volume of 6.
t lb» and a specific enthalpy of 9RO0 A bi/Abm. Find the internal energy per pound mass of steam A 2500 A-Ibb
95 Cac ulate^ the^ entropy^ of^ steam^ at^0 psia^ with^ a^ quality^ of^0 60 Properties of steam at 60 psia S = 04274 Btw/lb°R & Ss = 1 2172 Bru/b°R. A.0.4247 Btu/lb°R B.1.1577 Btu/lb°R
C.0.7303 Btu/h°R D. 0.896 Btulb°R
C. 5400 fn IbAb»
B. 3300 ft-Ib/lb D. 6900 ft Ib/lbm Solutinan:
S = Sr+x Ste 04274 + (0.60)X1.2172)
U H-PV =9800 1000(6.5)= 3300 ft-b/lb S = 1.1577 Btu/lb°R
Ans B AnsB
- The properties that are independent of the mass of the system such as temperature. pressure, density and voltage. A. Intensive properties B. Extensive properties C. Specitic properties D. State properties
- Wet saturated steam at 17 har ( he = 872 kJ/kg. hig = 1293 kJkg ) dryness
0.97 is produced from feedwater at 85°C ( h 335.9 kJ/kg ). Find the
heat energy supplied per kg. A. 4381.41 kJ/kg B. 1381.41I kJkg
C. 2381 41 kJ/kg D. 3381.41 kg
Solhon Heat energy supplied Increase in enthalpy
Answer. A Q h- h
where
h 355.9 kJ/kg
- The properties fora unit mass and are intensive by definition such as specific volume. A. Intensive properties B. Extensive properties C. Specific properties D. Thermmody namic properties
h2 hr + xhig
h2 872 + 0.97(1923)
h2 2737.31 kJkg
thus
Q 2737.31 - 355.9 = 2381.41 kJ/kg
Answer C
- The ratio of the gas constant to Avogadro's number is 97. The (^) properties of fluid at the (^) stagnation in state are called A. Maxwell s constant
B. Boltzmann'z constant A stagnation property
B. stagnation phase
C. stagnation state
D. stagnation vapor
C. Napier's constant D. Joule s constant Answer: B Answer: C
- Determine the average constant pressure specific heat of steam at 10 kPa
and 45.8°C. Note: From steam table, at 47.7°C, h= 2588.1 kg anda
43.8°C, h = 2581.1 kJ/kg. A. 1.79 kJ^g°C B. 10.28 kJkg°C
- A specific property
A. defines a specific variable (e.g.. temperature)
B. is independent of mass C. is an^ extensive property multipied^ by^ mass D. is dependent of the phase of the substance
C. 30.57 kIkg°C
D. 100.1 kg°C
Seltien:
AH
C T 588.1-2581.1 1.79 KJkg° Answer: A 47.7-43. Steam leaves an industrial boiler at 8274 kPa and 171.6°C ( h = 727. kJ/kg. hig = 2043.2 kJ/Ag ). A portion of the steam is passed through a throtling calorimeter and is exhausted to the atmosphere when the calorimeter pressure is 1014 kPa and a temperature of 115.6°C ( h = 2707.6 kJg }. How much moisture does the steam leaving the boiler
Ans. A eo
92. The device that measure temperature by the electromotive force called
themocouple was discovered by:
A. Galileo contain? A. 2.08 % C. 4.08 % B. Fahrenhiet (^) B. 3.08 % D. 5.08 %
C. Celsius
D. Seebeck Soletio
Answer: D (^) For throttling Process;
93. The^ tnple^ point^ of^ a^ substance^ is^ the^ lemperalure^ and^ pressure^
al which A. the solid and liquid phases are in equilibrium
B. the liquid and gaseous phases are in equilibriunm
C. the solid, liquid and the gaseous phases are in equlibrium
D. the solid does not melt, the liquid does not boil and the gas does not
hil +Khtg h
727.25 +x (2043.2) 2706.
X = 0. then; the moisture (y) is y=I-x = I - 0.97 3.08 %
condense Ans. B
Answer D 100. The device that measures temperalure by the elecromouve torce. A. themmometer
- According to Clausius statement A. Heat 1lows 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 ad of
B thermwcouple C. electuro thermoeter D. theruKoseebeck Answer B external work D. A and C Pkase log-0n lo wNYprLLIIeYKWCCLler Kon tor the enhancement ot Elenets(ems) u Mathenaties & Basic Enguncering Sciences, Power & Iachustrial Plant Engineering and Machne Desiga.
Answer: D
