PIPE 1 Flashcards
(161 cards)
1
Q
Find the work possess for a helium gas
at 20C.
A. 609 KJ/kg
B. 168 KJ/kg
C. 229 KJ/kg
D. 339 KJ/kg
A
A. 609 KJ/kg
2
Q
Two kilogram of gas is confned in a
1m³ tank 200kpa and 88°C. What
type of gas is in the tank?
A. Helium
B. Ethane
C. Methane
D. Ethane
A
B. Ethane
3
Q
Find the enthalpy of the helium if its
internal energy is 200KJ/Kg.
A. 144 kj/kg
B. 223.42 KJ/kg
C. 333.42 KJ/kg
D.168 KJ/kg
A
C. 333.42 KJ/kg
4
Q
Compute the mass of a 2m³ propane
at 280 kpa and 40°C
A. 6.47
B. 5.1
C. 10.20
D. 9.47
A
D. 9.47
5
Q
Compute the air flow in ft^3/min of
mechanical ventilation required to
exhaust an accumulation of refrigerant
due to leaks of the system capable of
revolving air from the machinery room
for a mass of 4lbs refrigerant.
A. 200
B. 210
C. 220
D. 230
A
A. 200
6
Q
Compute the free aperture cross
section in m² for the ventilation of a
machinery room in the mass of
refrigerant is 9kg.
A. 0.314
B. 0.414
C. 0.514
D.0.614
A
B. 0.414
7
Q
A 29.53” X 39.37” pressure vessel
contains ammonia with f=0.041.
compute the minimum required
discharge capacity of relief device in
kg/hr.
A. 106.71 kg/hr
B. 108.7 kg/hr
C. 110.71 kg/hr
D.112.71 kg/hr
A
C. 110.71 kg/hr
8
Q
Compute the maximum length of
discharge pipe installed on the outlet
of a pressure-relief device in feet for
the internal pipe diameter of 0.5 inch
and rated discharge capacity is
8lb/min of air. The rated pressure of
relief valve is 16psig.
A. 0.286 ft.
B. 0.386 ft.
C. 0.386 ft.
D.0.586 ft
A
A. 0.286 ft.
9
Q
A thermal power plant has a heat rate
of 11,363 Btu/kw-hr. find the thermal
efficiency of the plant.
A. 28%
B. 30%
C. 34%
D. 40%
A
B. 30%
10
Q
What is the hydraulic gradient of a 1
mile, 17 inches inside diameter pipe
when 3300 gal/ml of water flow with
f= .03?
A. 0.00714
B. 0.00614
C. 0.00234
D.0.00187
A
A. 0.00714
11
Q
Find the loss of head in the pipe
entrance if speed of flow is 10 m/s.
A. 5.10m
B. 10.2m
C. 17.4m
D. 2.55m
A
D. 2.55m
12
Q
Wet material containing 220%
moisture (dry basis) is to be dried at
the rate of 1.5 kg/s in a continuous
dryer to give a product containing
10% (dry basis). Find the moisture
removed, kg/hr.
A. 3543.75 kg/hr
B. 3513.75 kg/hr
C. 3563.75 kg/hr
D. 3593.75 kg/hr
A
A. 3543.75 kg/hr
13
Q
Copra enters a dryer containing 70%
moisture and leaves at 7% moisture.
Find the moisture removed on each
pound of solid in fnal product.
A. 6.528lb
B. 1.258lb
C. 4.258lb
D. 2.258 lb
A
D. 2.258 lb
14
Q
A 1m x 1.5m cylindrical tank is full of
oil with sg=0.92. fnd the force acting
at the bottom of the tank in dynes
A. 106.33 x 10^3
B. 106.33 x 10^4
C. 106.33 x 10^5
D.106.33 x 10^6
A
D.106.33 x 10^6
15
Q
Air at 10 deg. C and 80 Kpa enters a
difuser of a jet engine steadily with a
velocity of 200 m/s. The inlet area of
difuser is 0.40 m^2. Determine the
mass flow rate of air
A. 72.79 kg/s
B. 74.79 kg/s
C. 76.79 kg/s
D. 78.79 kg/s
A
D. 78.79 kg/s
16
Q
Consider a refrigeration whose 40
watts light bulb remains on
continuously as a result of
malfunction of the switch. If the
refrigerator has a COP of 1.3 and the
cost of electricity is 8 cents per kw-hr,
determine the increase in the energy
consumption of the refrigerator and
its cost per year if the switch is not
fxed.
A. P49.59
B. P47.59
C. P 45.59
D. P43.59
A
A. P49.59
17
Q
A 75hp motor that has an efficiency
of 91% is worn out and is replaced by
high-efficiency motor that has an
efficiency of 95.4%. Determine the
reduction in heat gain in room due to
higher efficiency under full load
conditions.
A. 2.24 KW
B. 2.44 KW
C. 2.64 KW
D. 2.84 KW
A
B. 2.44 KW
18
Q
A household refrigerator that has a
power input of 450 watts and COP of
2.5 is to cool fve large watermelons,
10 kg each, if the watermelons are
initially at 20 deg. C, determine how
long will take for the refrigerator to
cool them. the watermelons can be
treated as water whose specifc heat
is 4.2 KJ/kg-K.
A. 2220 seconds
B. 2230 seconds
C. 2240 seconds
D. 2250 seconds
A
C. 2240 seconds
19
Q
When a man returns to his wall-
sealed house on a summer day, he
fnds that the house is at 32 deg. C.
he turned on the air conditioner which
cools the entire house to 20 deg. C in
15 minutes. If COP is 2.5, determine
the power drawn by the air-
conditioner. Assume the entire mass
within the house is 800 kg of air for
which Cv = 0.72 KJ/kg-K, Cp = 1.0
KJ/kg-K.
A. 1.072 KW
B. 2.072 KW
C. 3.072 KW
D. 4.702 KW
A
C. 3.072 KW
20
Q
A heat source at 800 K losses 2000 KJ
of heat to a sink at 500 K. Determine
the entropy generated during this
process.
A. 1.5 KJ./kg
B. 2.5 KJ/kg
C. -2.5 KJ/kg
D. 4 KJ/kg
A
A. 1.5 KJ./kg
21
Q
A helium gas is compressed on in an
adiabatic compressor from an initial
state of 14 psia and 50 deg. F to a
fnal temperature of 320 deg F in a
reversible manner. Determine the exit
pressure of helium.
A. 38.5 psia
B. 40.5 psia
C. 42.5 psia
D. 44.5 psia
A
B. 40.5 psia
22
Q
Air pass thru a nozzle with efficiency
of 90%. The velocity of air at the exit
is 600 m/s. fnd the actual velocity at
the exit.
A. 382 m/s
B. 540 m/s
C. 458 m/s
D. 568 m/s
A
D. 568 m/s
23
Q
A 50 kg of iron casting at 500 K is
thrown into a large lake that is at
temperature of 285 K. the iron block
eventually reaches thermal
equilibrium with the lake water.
Assuming average specifc heat of
0.45 KJ/kg-K for the iron, determine
the entropy generated during this
process.
A. -12.65 KJ/K
B. 16.97 KJ/K
C. 4.32 KJ/K
D. 6.32 KJ/K
A
C. 4.32 KJ/K
24
Q
A windmill with a 12 m diameter rotor
is to be installed at location where the
wind is blowing at an average velocity
of 10 m/s. Using standard condition of
air (1 atm, 25 deg. C), determine the
maximum power that can be
generated by the windmill.
A. 68 KW
B. 70 KW
C. 72 KW
D. 74 KW
A
B. 70 KW
25
Consider a large furnace that can
supply heat at temperature of 2000
deg. R at a steady rate of 3000 Btu/s.
Determine the exergy of this energy.
Assume an environment temperature
of 77 deg. F.
A. 205.19 KW
B. 2315.19 KW
C. 2325.19 KW
D. 2335.19 KW
B. 2315.19 KW
26
A heat engine receives heat from a
source at 1200 deg. K at rate of 500
KJ/s and rejects the waste heat to a
medium at 300 deg. K. the power
output of the heat engine is 180 KW.
Determine the irreversibility rate for
this process.
A. 190 KW
B. 195 KW
C. 200 KW
D. 205 KW
B. 195 KW
27
A dealer advertise that he has just
received a shipment of electric
resistance heaters for residential
buildings that have an efficiency of
100 percent. Assuming an indoor
temperature of 21 deg. C and outdoor
temperature of 10 deg. C, Determine
the second law efficiency of these
heaters.
A. 8.74 %
B. 6.75 %
C. 3.74 %
D. 4.74 %
C. 3.74 %
28
A thermal power plant has a heat rate
of 11,363 Btu/hr. fnd the thermal
efficiency of the plant.
A. 34 %
B. 24 %
C. 26 %
D. 30 %
D. 30 %
29
A rigid tank contains 2 kmol of N2
and 6 kmol of CO2 gases at 300 deg.
K and 115 Mpa. Find the tank volume
using ideal gas equation.
A. 7.33 m^3
B. 5.33 m^3
C. 3.33 m^3
D. 1.33 m^3
D. 1.33 m^3
30
A spherical balloon with a diameter of
6 m is flled with helium at 20 deg. C
and 200 Kpa. Determine the mole
number.
A. 9.28 Kmol
B. 10.28 Kmol
C. 11.28 Kmol
D. 13.28 Kmol
A. 9.28 Kmol
31
The air in an automobile tire with a
volume of 0.53 ft^3 is at 90 deg. F
and 20 psig. Determine the amount of
air that must be added to raise the
pressure to the recommended value
of 30 psig. Assume the atmospheric
pressure to be 14.6 psia and the
temperature and the volume to
remain constant.
A. 0.026 lb
B. 0.046 lb
C. 0.066 lb
D. 0.086 lb
A. 0.026 lb
32
A rigid tank contains 20 lbm of air at
20 psia and 70 deg. F. more air is
added to the tank until the pressure
and temperature rise to 35 psia and
90 deg. F, respectively. Determine the
amount of air added to the tank.
A. 11.73 lb
B. 13.73 lb
C. 15.73 lb
D. 17.73 lb
B. 13.73 lb
33
A rigid tank contains 5 kg of an ideal
gas at 4 atm and 40 deg. C. Now a
valve is opened, and half of mass of
the gas is allowed to escape. If the
fnal pressure in the tank is 1.5 atm.
The fnal temperature in the tanks is:
A. -39 deg. C
B. -30 deg. C
C. 40 deg. C
D. 53 deg. C
A. -39 deg. C
34
The pressure of an automobile tire is
measured to be 200 Kpa (gage)
before the trip and 220 kpa (gage)
after the trip at a location where the
atmospheric pressure is 90 kpa. If the
temperature of the air in the tire
before the trip is 25 deg. C, the air
temperature after the trip is:
A. 45.6 deg. C
B. 54.8 deg C.
C. 27.5 deg. C
D. 26.7 deg. C
A. 45.6 deg. C
35
Water boils at 1 atm pressure in a
stainless steel pan on an electric
range. It is observed that 2 kg of
liquid water evaporates in 30 min. the
rate of heat transfer to the water is
A. 2.97 KW
B. 0.47 KW
C. 2.51 KW
D. 3.12 KW
C. 2.51 KW
36
Consider a person standing on a
breezy room at 20 deg. C. Determine
the total rate of heat transfer from this
person if the exposed surface area and
the average outer surface
temperature of the person are 1.6
m^2 and 29 deg. C respectively, and
the convection heat transfer
coefficient is 6 W/m^2 with the
emissivity factor of 0.95.
A. 86.40 watts
B. 81.70 watts
C. 198.1 watts
D. 168.1 watts
D. 168.1 watts
37
Water is boiling in a pan on a stove at
sea level. During 10 minutes of
boiling, it is observed that 200 grams
of water has evaporated. Then the
rate of heat transfer to the water is:
A. 0.84 KJ/min
B. 45.1 KJ/min
C. 41.8 KJ/min
D. 53.5 KJ/min
B. 45.1 KJ/min
38
In a brayton cycle that operates
between temperature limits of 300K
and 1773K with K = 1.4, determine the
temperature at the end of the
compression (isentropic) for maximum
work of the cycle.
A. 700K
B. 690.5K
C. 730K
D. 350K
C. 730K
39
At 35% solution leaves the absorber
and 30% solution enters the absorber.
The heat removed from the absorber
by cooling water is 547.6 Btu and
ammonia is superheated by 10deg.
Find the pound per pound of ammonia
gas from the evaporating coils.
A. 11
B. 12
C. 13
D. 14
C. 13
40
A carnot refrigeration system
operates at Tmax./Tmin.=1.5, Find
the KW per to of refrigeration.
A. 1.91
B. 2.15
C. 1.76
D. 1.55
C. 1.76
41
Assume 8ft^3 of air at 100psi,
100degF are compressed isothermally
to a volume of 2ft^3. For each of end
state the process, fnd the bulk
modulus.
A. 400 and 100 psi
B. 400 and 110 psi
C. 400 and 120 psi
D. 400 and 130 psi
A. 400 and 100 psi
42
Predict the pressure of nitrogen gas
at T=200K and v=0.00385
m^3/kg and b=0.00141 m^3/kg;
a=0.178 m^2 kpa/kg^2. Use van
der waals equation,
A. 15,331 kpa
B. 14,331 kpa
C. 13,331 kpa
D. 12,331 kpa
D. 12,331 kpa
43
Francis turbine is to be operated at a
speed of 600rpm and with discharge
of 4m^3/s. if r1=0.6m,
beta1=110deg, and the blade height B
is 10cm, what should be the guide
angle a1 for non-separating flow
condition at the runner entrance ?
A. 14.4 deg
B. 15.4 deg
C. 16.4 deg
D. 17.4 deg
D. 17.4 deg
44
The total head of fan is 187m and has
a static pressure of 210mm of water
gage, what is the velocity of air
flowing if density of air is 1.15 kg/m^3
?
A. 6.85 m/sec
B. 3.45 m/sec
C. 4.39 m/sec
D. 9.28 m/sec
D. 9.28 m/sec
45
A fan delivers 5.7 m^3/sec. at a static
pressure of 5.08 cm of water when
operating at a speed of 400rpm. The
power input required is 2.963 KW. If
7.05 m^3/sec. are desired in the same
fan and installation, fnd the pressure
in cm of water.
A. 7.77
B. 17.14
C. 11.43
D. 5.08
A. 7.77
46
A rigid container is closed at one end
and measures 8 in diameter by 12 in
long. The container is held vertices
and slowly moved downward until the
pressure in the container is 17psia.
What will be the depth of the top of
the container from the free water
surface?
A. 42.36in
B. 59.29in
C. 63.69in
D. 69.82in
C. 63.69in
47
A turbo-charged, 16 cylinder, Vee-type
diesel engine has an air consumption
of 3,000 kg/hr per cylinder at rated
load and speed, this air is drawn in
through a flter by a centrifugal
compressor directly connected to the
exhaust gas turbine. The temperature
of the air from the compressor is 135
DegC and a counter flow air cooler
reduces the air temperature to 45
degC before it goes to the engine
suction header. Cooling water enters
air cooler 30 degC and leaves at 40
degC. Calculate the log mean
temperature diference.
A. 47.23 DegC
B. 87.82 degC
C. 43.34 degC
D. 65.42 degC
C. 43.34 degC
48
Water is flowing in a pipe with radius
of 30 cm at a velocity of 5 m/sec at
the temperature in the pipe. The
density and viscosity of the water are
as follows density = 997.9 kg/sec
viscosity = 1.131 Pa. what is the
Reynolds number of this situation?
A. 2847
B. 96.2
C. 3100
D. 140
A. 2847
49
Compute the amount of condensate
form during 10 minutes warm-up of
180 meter pipe conveyors the
saturated steam with enthalpy
vaporization hfg = 1,947.6 kj/kg. the
minimum external temperature of pipe
is 2 DegC. The fnal temperature of
pipe is 195 degC. The specifc heat of
pipe material is 0.6 kj/kg-C. the
specifc weight if 28 g/m.
A. 249.69 kg
B. 982.45 kg
C. 299.64 kg
D. 423.45 kg
C. 299.64 kg
50
The discharge pressure of an air
compressor is 5 times the suction
pressure. If volume flow at suction is
0.1 m^3/sec. what is the suction
pressure if compressor work is 19.57
kw? (use n = 1.35)
A. 97 Kpa
B. 98 Kpa
C. 99 Kpa
D. 100 Kpa
B. 98 Kpa
51
The initial condition of air in an air
compressor is 93 Kpa and 27 deg. C
and discharges air at 450 Kpa. The
bore and stroke are 355 mm and 381
mm, respectively with percent
clearance of 8% running at 300 rpm.
Find he volume of air at suction.
A. 541.62 m^3/hr
B. 551.62 m^3/hr
C. 561.62 m^3/hr
D. 571.62m^3/hr
D. 571.62m^3/hr
52
An air compressor has a suction
volume of 0.35 m^3/sec at 97 Kpa
and discharges to 650 Kpa. How
much power is saved by the
compressor if there are two stages?
A. 27 KW
B. 16.54 KW
C. 13.86 KW
D. 11.58 KW
D. 11.58 KW
53
A two-stage air compressor has an
intercooler pressure of 4 kg/cm^2.
What is the discharge pressure if
suction pressure is 1 kg/cm^2?
A. 3 kg/cm^2
B. 9 kg/cm^2
C. 12 kg/cm^2
D. 16 kg/cm^2
D. 16 kg/cm^2
54
A two-stage air compressor air at 100
Kpa and 22 deg. C discharges to 750
Kpa. If the intercooler intake is 105
deg. C, Determine the value of n.
A. 1.400
B. 1.326
C. 1.345
D. 1.288
D. 1.288
55
A single acting air compressor has a
volumetric efficiency of 89%, operates
at 500 rpm. It takes in air at 100 Kpa
and 30 deg. C and discharges it at 600
Kpa. The air handled is 8 m^3/min
measured at discharge condition. If
compression is isentropic, fnd mean
efective pressure in Kpa.
A. 233.34
B. 973.17
C. 198.34
D. 204.82
A. 233.34
56
Water-jacketed air compressor handles
.0343 m^3/s of air entering at
96.5Kpa and 21 deg. C and leaving at
480 Kpa and 132 deg. C; 10.9 kg/h of
cooling water enters the jacket at 15
deg. C and leaves at 21 deg. C,
Determine the compressor brake
power?
A. 26.163 kw
B. 62.650 kw
C. 84.44 kw
D. 19.33 kw
B. 62.650 kw
57
A double suction centrifugal pumps
delivers 20 ft^3/sec of water at head
of 12 m and running at 650 rpm. What
is the specifc speed of the pump?
A. 5014.12 rpm
B. 6453.12 rpm
C. 2770.73 rpm
D. 9968.73 rpm
C. 2770.73 rpm
58
Determine the number of stages
needed for a centrifugal pump(s) if it
used to deliver 400 gal/min of water
and pump power of 15 Hp. Each
impeller develops a head of 30 ft.
A. 8
B. 4
C. 5
D. 7
C. 5
59
The suction pressure of a pump reads
3 in. of mercury vacuum and
discharge pressure reads 140 psi is
use to deliver 120 gpm of water with
specifc volume of 0.0163 ft^3/lb.
Determine the pump work.
A. 4.6 KW
B. 5.7 KW
C. 7.4 KW
D. 8.4 KW
60
A submersible pump delivers 350 gpm
of water to a height of 5 ft from the
ground. The pump was installed 150 m
below the ground level and a
drawdown of 8 ft during the operation,
if the water level is 25 ft above the
pump, determine the pump power.
A. 7.13 KW
B. 4.86 KW
C. 7.24 KW
D. 9.27 KW
D. 9.27 KW
61
A vacuum pump is used to drain a
flooded mine shaft of 20 deg. C water.
The pump pressure of water at this
temperature is 2.34 Kpa. The pump is
incapable of lifting the water higher
than 16 m. what is the atmospheric
pressure.
A. 159.30
B. 132.33
C. 198.22
D. 171.9
A. 159.30
62
A submersible, multi-stage, centrifugal
deep well pump 260 gpm capacity is
installed in a well 27 feet below the
static water level and running at 3000
rpm. Drawdown when pumping at
rated capacity is 10 feet. The pump
delivers the water into a 25,000
gallons capacity overhead storage
tank. Total discharge head developed
by pump, including friction in piping is
243 feet. Calculate the diameter of the
impeller of this pump in inches if each
impeller diameter developed a head of
38 ft.
A. 3.28
B. 5.33
C. 3.71
D. 6.34
C. 3.71
63
A fan draws 1.42 m^3 per second of
air at a static pressure of 2.54 cm of
water through a duct 300 mm
diameter and discharges it through a
duct of 275 mm diameter. Determine
the static fan efficiency if total fan
mechanical is 75% and air is
measured at 25 deg. C and 760 mm
Hg.
A. 50.11%
B. 53.69%
C. 65.67%
D. 45.34%
B. 53.69%
64
A water cooler uses 50lb/hr of meltingice to cool running water from 80deg F
to 42deg F. based on the inside coil
area U=110 btu/hr-ft^2-F. Find the
gpm of water cooled.
A. 0.10 GPM
B. 0.21 GPM
C. 0.38 GPM
D. 0.45 GPM
C. 0.38 GPM
65
The charge in a diesel engine consist
of 18.34 grams of fuel, with lower
heating value of 42,571 KJ/KG, and
409 grams of fuel and products of
combustion. At the beginning of
compression, t1-60degC, let Rk=14.
For constant Cp=1.11 KJ/KG-C, what
should be the cut-of ratio in the
corresponding ideal cycle ?
A. 2.05
B. 2.34
C. 5.34
D. 2.79
D. 2.79
66
The gain of entropy during nonflow
process of 5lb of air at 60degF is 0.162
Btu/R. fnd the V1/V2
A. 3.35
B. 0.259
C. 1.0
D. 0.296
B. 0.259
67
An auditorium seating 1500 people is
to be maintained at 80degF dry bulb
and 65degF wet bulb temp. when
outdoor air is at 91degfF dry bulb and
75degF wet bulb. Solar heat load is
110,000 btu/hr and supply air is at
60degF, determine the amount of air
supply.
A. 93,299.17 lb/hr
B. 83,299.17 lb/hr
C. 73,299.17 lb/hr
D. 63,299.17 lb/hr
A. 93,299.17 lb/hr
68
An engine-generated rated 9000 KVA
at 80% power factor, 3 phase, 4160 V
has an efficiency of 90%. If overall
plant efficiency is 28%, what is the
heat generated by the fuel?
A. 18,800 KW
B. 28,800 KW
C. 7,500 KW
D. 25,714 KW
D. 25,714 KW
69
The indicated thermal efficiency of a
two-stroke diesel engine is 60%. If the
friction power is 15% of the heat
generated, determine the brake
thermal efficiency of the engine.
A. 43%
B. 45%
C. 38%
D. 37%
B. 45%
70
A 305 mm x 457 mm four stroke
single acting diesel engine is rated at
150 KW at 260 rpm. Fuel consumption
at rated load is 0.56 Kg/Kw-hr with a
heating value of 43,912 kj/kg.
Calculate brake thermal efficiency.
A. 10.53%
B. 27.45%
C. 14.64%
D. 18.23%
C. 14.64%
71
A waste heat recovery boiler produces
4.8 Mpa (dry Saturated) steam from
104 deg C feed water. The boiler
receives energy from 7 kg/sec of 954
deg C dry air. After passing through
the waste heat boiler, the temperature
of the air has been reduced to 343
degC. How much steam in kg is
produced per second? Note at 4.60
Mpa dry saturated, h = 2796.
A. 1.30
B. 0.92
C. 1.81
D. 3.43
C. 1.81
72
Diesel electric plant supplies energy
for meralco, during a 24-hour period,
the plant consumed 240 gallons of fuel
at 28 degC and produced 3930 KW-hr.
industrial fuel used is 28 deg API and
was purchased at P30 per liter at 15.6
degC. What is the cost of fuel to be
produced one KW-hr?
A. 6.87
B. 1.10
C. 41.07
D. 5.00
A. 6.87
73
In a gas turbine unit, air enters the
combustion chamber at 550 Kpa, 227
degC and 43 m/s. the products of
combustion leave the combustor at
511 Kpa, 1004 degC and 180 m/s.
liquid fuel enters with a heating value of 43,000 kj/kg. for Fuel-air ratio of
0.0029. what is the combustor
efficiency of the unit in percent?
A. 70.38%
B. 79.30%
C. 75.38%
D. 82.38%
C. 75.38%
74
The specifc speed of turbine is 85 rpm
and running at 450 rpm. If the head is
20 m and generator efficiency is 90%.
What is the maximum power delivered
by the generator?
A. 450.51 KW
B. 354.52 KW
C. 650.53 KW
D. 835.57 KW
D. 835.57 KW
75
A perfect gas has a value of R= 58.8
ft-lb/lb-R and K= 1.26. if 20 Btu are
added to 10 lbs of his gas at constant
volume when initial temperature is 90
degF fnd the fnal temperature.
A. 97 degF
B. 104 degF
C. 154 degF
D. 185degF
A. 97 degF
76
Ammonia weighing 22 kgs is
confrmed inside a cylinder equipped
with a piston has an initial pressure of
413 Kpa at 35 degC if 3200 KJ of heat
is added to the ammonia until its fnal
pressure and temperature are 413 Kpa
and 100 DegC respectively, what is
the amount of work done by the fluid
in KJ?
A. 667
B. 304
C. 420
D. 502
A. 667
77
A tank contains 90 ft^3 of air at a
pressure of 350 Psig; of the air is
cooled until its pressure and
temperature decreases to 200 Psig
and 70 DegF respectively, what is the
decrease in internal energy?
A. 6232.09 Btu
B. -5552 Btu
C. 5552 Btu
D.-6232.09 Btu
D.-6232.09 Btu
78
A large mining company was provided
with a 3 m^3 of compressed air tank.
Air pressure in the tank drops from
700 kpa to 160 kpa while the
temperature remains constants at 28
degC, what percentage has the mass
of air in the tank been reduced?
A. 74.00
B. 72.45
C. 76.56
D.78.57
D.78.57
79
A 4 m^3/hr pump delivers water to a
pressure tank. At the start, the gage
reads 138 Kpa until reads 276 KPa and
then pump was shut of. The volume
of the tank is 100 liters. At 276 Kpa
the water occupied 2/3 of the tank
volume. Determine the volume of
water that can be taken out until the
gage reads 138 Kpa.
A. 31.20 liters
B. 34.59 liters
C. 16.67 liters
D. 29.50 liters
B. 34.59 liters
80
A refrigeration plant is rated at 15 tons
capacity. How many pounds of air per
hour will it cool from 70 to 90 DegF at
constant pressure.
A. 50,000 lb/hr
B. 37,500 lb/hr
C. 52,000 lb/hr
D. 45,000 lb/hr
B. 37,500 lb/hr
81
an air standard engine has a
compression ratio 18 and a cut-of
ratio 4. If the intake air pressure and
temperature are 100 kpa and 27deg C,
fnd the work in KJ per kg.
A. 2976
B. 2166
C. 1582
D. 2751
D. 2751
82
determine the air standard efficiency
of an operating on the diesel cycle
with clearance of 6%, when the
suction pressure is 99.97 kpa and the
fuel is injected for 7% of the stroke.
Assume k=1.4.
A. 62.11%
B. 51.20%
C. 73.58%
D. 60.02%
A. 62.11%
83
steam at 2Mpa and 250deg C in a rigid
cylinder is cooled until the quality is
30%. Find the heat rejected from the
cylinder.
A. -432.23
B. -926.26
C. -1265.02
D. 1082.34
C. -1265.02
84
The following coal has the following
ultimate analysis by weight:
C = 70.5% H2 = 4.5% O2 = 6.0%
N2 = 1.0%
S =3.0% Ash = 11%
Moisture = 4%
A stocker fred boiler of 195,00 kg/hr
steaming capacity used this coal as
fuel. Calculate the volume of air in
m^3/hr with air at 60 deg. F and 14.7
psia pressure if boiler efficiency is 70%
and FE = 1.10
A. 234,019 m^3/hr
B. 215,830 m^3/hr
C. 213,830 m^3/hr
D. 264,830 m^3/hr
A. 234,019 m^3/hr
85
23.5 kg of steam per second at 5 Mpa
and 400 deg. C is produced by a
steam generator. The feedwater
enters the economizer at 145 deg. C
and leaves at 205 deg. C. the steam
leaves the boiler drum with a quality
of 98%. The unit consumes 3 kg of
coal per second as received having a
heating value of 25,102 KJ/kg. What
would be the overall efficiency of the
unit in percent?
Steam properties :
At 5 Mpa and 400 deg. C: h = 3195.7
KJ/kg
at 5 Mpa; hf = 1154.23, hfg = 1640.1
At 205 deg C: hf = 875.04 at
145 deg. C: hf = 1640.1
A. 65.72
B. 80.67
C. 88.28
D. 78.8
B. 80.67
86
In a Rankine cycle steam enters the
turbine the turbine at 2.5 Mpa
(enthalpies and entropies given) and
condenser of 50 kPa (properties are
given) what is the thermal efficiency of
the cycle?
A. 25.55%
B. 45.23%
C. 34.23%
D. 12.34%
A. 25.55%
87
A thermal power plant generates 5
MW and the heat generated by the
fuel is 13,000 Kj/sec. if the thermal
efficiency is 6.15%, fnd the power
needed for the auxiliaries.
A. 310 Kw
B. 300 Kw
C. 400 Kw
D. 350 Kw
B. 300 Kw
88
Francis Turbine, the Pressure gage
leading to the turbine casing reads
380 Kpa. The velocity of water
entering a turbine is 0 m/sec, if net
head of the turbine is 45m. fnd the
distance from center of spiral casing to
the ….
A. 3.0 m
B. 3.5 m
C. 4.0 m
D. 4.5 m
A. 3.0 m
89
A turbine has a mechanical efficiency
of 93% volumetric efficiency of 95%
and total efficiency of 82%. If the
efective head is 40m, fnd the total
head.
A. 48.72 m
B. 40.72 m
C. 36.22 m
D. 34.72 m
C. 36.22 m
90
Pelton Type turbine has 25 m head
friction loss of 4.5 m. the total
coefficient of friction head loss (from
morse) is 0.00093 and penstock
length of 80 m, what is the penstock
diameter?
A. 1,355.73 mm
B. 3,476.12 mm
C. 6,771.23 mm
D. 1686.73 mm
A. 1,355.73 mm
91
In a 9,000 KW hydro-electric power
plant the over-all efficiency is 88% and
the actual power received by the
customer is 110,000 Kw-hrs for that
day. What is the secondary power
could this plant deliver during the
entire day?
A. 58,960 KW
B. 80,080 KW
C. 65,960 KW
D. 70,960 KW
B. 80,080 KW
92
Pelton type turbine was installed 30 m
below the head gate of the penstock.
The head loss due to friction is 12% of
the given elevation. The length of
penstock is 100 m and coefficient of
friction is 0.00093 determine the
power output in KW (use morse
equation)
A. 22,273
B. 23,234
C. 32,345
D. 34,452
D. 34,452
93
Water flows steadily with a velocity of
3.05 m/s in a horizontal pipe having a
diameter of 25.24 cm. at one action of
the pipe the temperature and pressure
of the water are 21 degC and 689.3
Kpa, respectively. At a distance of
304.8 m downstream, the pressure is
516.9 Kpa. What is the friction factor?
A. 0.135
B. 0.0050
C. 0.0307
D. 0.641
C. 0.0307
94
A hydro-electric plant having a 30 sq.
km reservoir area and 100 m head is
used to generate power. The energy
utilized by the consumers whose load
is connected to the power plant during
a fve-hour period is 13.5 x 10^6 Kwh.
The overall generation efficiency is
75%. Find the fall in height of water in
the reservoir after the 5-hour period.
A. 5.13 m
B. 1.32 m
C. 3.21 m
D. 2.20 m
D. 2.20 m
95
The gas density of chimney is 0.75
kg/m^3 and air density of 1.15
kg/m^3. Find the driving pressure if
the height of chimney is 63.71 m
A. 0.15 KPa
B. 0.25 Kpa
C. 0.35 Kpa
D. 0.45 Kpa
B. 0.25 Kpa
96
The actual velocity of gas entering in a
chimney is 8 m/sec. the gas
temperature is 25 degC with a gas
constant of 0.267 kj/kg-K. determine
the gas pressure for a mass of gas is
50,00 kg/hr and chimney diameter of
1.39 m
A. 95 Kpa
B. 98 Kpa
C. 101 kpa
D. 92 Kpa
B. 98 Kpa
97
A steam generator with economizer
and air heater has an overall draft loss
of 25.78 cm of water. If the stack
gases are at 177 DegC and if the
atmosphere is at 101.3 Kpa and 28
DegC. What theoretical height of stack
in meters is needed when no draft fan
are used? Assume that the gas
constant for the flue gasses is the
same as that for air.
A. 811.10
B. 631.10
C. 651.10
D. 671.10
C. 651.10
98
A foundation measures 12 ft x 14 ft x
15 ft. fnd the number of sacks of
cement needed for 1:2:4 mixture
A. 302
B. 404
C. 356
D. 598
D. 598
99
A rectangular foundation cross-section
has a bed plate dimension of 8 ft x 10
ft. the uniform clearance on each side
is 1 ft. the height of foundation is 4.5
ft. if the weight of the steel bar
reinforcements needed is ½% of
weight of foundation, fnd the weight
of steel bars, use concrete density of
2400 Kg/m^3.
A. 173.47
B. 183.47
C. 163.47
D. 153.47
B. 183.47
100
A steam pipe having a surface
temperature of 250 degC passes
through a room where the
temperature is 27 DegC the outside
diameter of pipe is 100 mm and
emissivity factor is 0.8 calculate the
radiated headloss for 3m be length.
A. 1,434.47 W
B. 3,746.35 W
C. 2,851 W
D. 3,546.45 W
C. 2,851 W
101
Brine enters a circulating brine cooler
at the rate of 80 m%3/hr at -8 degC,
specifc heat of brine is 1.072 kJ/kg-K
and specifc gravity of 1.12. determine
the tons of refrigeration.
A. 53.5 TR
B. 65.3 TR
C. 33.5 TR
D. 56.9 TR
D. 56.9 TR
102
At 1.8 Mpa, mixture steam and water
has an entropy of 3 KJ/kg Deg K. fnd
the enthalpy of the mixture.
A. 1,627.11KJ/kg
B. 1,533.33 KJ/kg
C. 1,234.45 KJ/kg
D. 1,162.40 KJ/kg
D. 1,162.40 KJ/kg
103
Mixture with 70% quality at 500kpa is
heated isothermally until its pressure
is 300kpa. Find the heat added during
the process.
A. 745.92KJ/kg
B. 535.16 KJ/kg
C. 983.44 KJ/kg
D. 765.34 KJ/kg
A. 745.92KJ/kg
104
A tank contains exactly one kilogram
of water consisting of liquid and vapor
in equilibrium at Mpa. If the liquid
contains one-third and the remaining
is vapor of the volume of the tank,
what is the enthalpy of the contents of
the tank?
A. 644.40 KJ/kg
B. 774.40 KJ/kg
C. 785.92 KJ/kg
D. 435.29 KJ/kg
C. 785.92 KJ/kg
105
Water substance at 70 bar and 65
degC enters a boiler tube of constant
inside diameter of 25mm. the water
leaves the boiler tube at 50 bar and
700degK at velocity of 150m/s/
calculate the inlet velocity(m/sec)
A. 1.56
B. 2.51
C. 1.672
D. 3.230
B. 2.51
106
Water substance at 70 bar and 65
degC enters a boiler tube of constant
inside diameter of 35mm. the water
leaves the boiler tube at 50 bar and
700degK at velocity of 100m/s/
calculate the inlet volume flow (li/sec)
A. 0.821
B. 1.261
C. 0.344
D. 1.609
D. 1.609
107
Steam leaves an industrial boiler at
827.4 Kpa and 171.6 deg. C. A portion
of the steam is passed through a
throttling calorimeter and is exhausted
to the atmosphere when the
calorimeter pressure is 101.4 Kpa.
How much moisture does the steam
leaving the boiler contain if the
temperature of the steam at the
calorimeter is 115.6 Deg. C.
A. 3.78%
B. 3.08%
C. 4.56%
D. 2.34%
B. 3.08%
108
A throttling is connected to the
desuperheated steam line supplying
steam to the auxiliary feed pump on a
ship. The line pressure measures 2.5
Mpa. The calorimeter pressure is 110
Kpa and 150 deg. C. determine the
entropy of the steam line.
A. 6.8 KJ/Kg-K
B. 6.2 KJ/Kg-k
C. 6.6 KJ/Kg-k
D. 7.5 KJ/Kg-k
B. 6.2 KJ/Kg-k
109
Atmospheric pressure at boils 212
deg. F. At the vacuum pressure at 24
in. Hg, the temperature is 142 deg F.
Find the boiling temperature when the
pressure is increased by 40 psia from atmospheric.
A. 449.42 F
B. 526.34 F
C. 479.13 F
D. 263.45 F
A. 449.42 F
110
A certain coal has the following
ultimate analysis:
C = 69% N2 = 5%
H2 = 2.5% S = 7%
Determine the amount of oxygen if the
heating value of fuel is 26,961.45
KJ/Kg.
A. 1.5%
B. 2.5%
C. 3.5%
D. 4.5%
D. 4.5%
111
A diesel engine consumed 946 liters of
fuel per day at 35 deg. C. if the fuel
was purchased at 15.6 deg. C and 30
deg. API at P29.00/li, determine the
cost of fuel to operate the engine per
day.
A. P5677.50
B. P4677.50
C. P48,088.90
D. P27,127.76
D. P27,127.76
112
A cylindrical tank 4m long and 3m
diameter is used for oil storage. How
many days can the tank supply the
engine having 27 deg. API with fuel
consumption of 60 kg/hr?
A. 17.53
B. 5.84
C. 12.84
D. 19.84
A. 17.53
113
A logging frm in Isabella operates a
Diesel Electric Plant to supply it’s
electric energy requirements. During a
24 hour period, the plant consumed
250 gallons of fuel at 80 deg. F and
produced 2900 KW-hrs. Industrial fuel
used is 30 deg. API and was purchased
at P30.00/li at 60 deg. F. Determine
the overall thermal efficiency of the
plant.
A. 26.08%
B. 34.23%
C. 28.00%
D. 18.46%
C. 28.00%
114
The dry exhaust gas from oil engine
has the following gravimetric
analysis :
CO2 = 21.6% O2 = 4.2%
N2 = 74.2%
Specifc heats at constant pressure for
each component of the exhaust gas in
Kcal/kg-C are:
CO2 = 0.203O2 = 0.219 N2 = 0.248
Calculate the specifc gravity if the
molecular weight of air is 28.97 kg/kg-
mol
A. 0.981
B. 1.244
C. 1.055
D. 0.542
C. 1.055
115
A bituminous coal has the following
composition:
C= 71.5% H = 5.0% O = 7.0%
N = 1.3% S = 3% Ash =
7.6% W = 3.4%
Determine the theoretical weight of
Nitrogen in lb/lb of coal
A. 2.870
B. 7.526
C. 2.274
D. 6.233
B. 7.526
116
A gaseous fuel mixture has a molal
analysis:
H2 = 14% CH4 = 3% CO = 27%
O2 = 0.6% CO2 = 4.5% N2 = 50.9%
Determine the air-fuel ratio for
complete combustion on molal basis.
A. 2.130
B. 3.230
C. 1.233
D. 1.130
C. 1.233
117
A volumetric analysis of a gas mixture
is as follows:
CO2 : 12%
O2 : 4%
N2 : 80%
CO4 : 4%
What is the percentage of CO2 on a
mass basis?
A. 17.55%
B. 15.55%
C. 12.73%
D. 19.73%
A. 17.55%
118
A diesel cycle has a cut of ratio of 2.5
and expansion ratio of 4. Find the
clearance of cycle.
A. 9.11%
B. 5.55%
C. 11.11%
D. 15.15%
C. 11.11%
119
A dual cycle has an initial temperature
of 30C. the compression ratio is 6 and
the heat addition at constant volume
process is 600kj/kg. if cut of ratio is
2.5, fnd the maximum temperature of
the cycle.
A. 3638.50 deg C
B. 3365.50 deg C
C. 3565.50 deg C
D. 3965.50 deg C
B. 3365.50 deg C
120
A three stages air compressor
compresses air from 100kpa to
1000kpa. Find the intercooler pressure
between the frst and second stage.
A. 505.44kpa
B. 108.44kpa
C. 316.23kpa
D. 215.44kpa
D. 215.44kpa
121
A 10—stages air compressor
compresses air from 100kpa to
800kpa. Find the intercooler pressure
between the frst and second stage.
A. 282.84 kpa
B. 113.21 kpa
C. 123.11 kpa
D. 333.51 kpa
C. 123.11 kpa
122
A 3 stages air compressor compresses
air from 100kpa to 700kpa. Find the
intercooler pressure between 2nd
and 3rd
stage
A. 365.88 kpa
B. 375.88 kpa
C. 385.88 kpa
D. 395.88 kpa
A. 365.88 kpa
123
Carnot cycle a,b,c are connected in
series so that the heat rejected from a
will be the heat added to B an heat
rejected from b will be added to c.
each cycle operates between 30degC
and 400degC. If heat added to A is
1000kw, fnd the work output of C.
A. 111.4 kw
B. 549.78 kw
C. 247.53 kw
D. 141.89 kw
A. 111.4 kw
124
Air is compressed adiabatically from
30degC to 100degC. If mass of air
being compressed is 5kg, Find the
change of entropy?
A. 1.039 kj/kg
B. 0.746 kj/kg
C. 0
D. 1.245 kj/kg
C. 0
125
Two kilogram of air in a rigid tank
changes its temperature from 32degC
to 150degC. Find the work done during
the process.
A. 236
B. 170
C. 195
D. 0
D. 0
126
Determine the atmospheric pressure
at a location where barometric reading
is 740mm Hg and gravitational
acceleration is g = 9.7m/s^2. Assume
the temperature of mercury to be 10
deg.C at which the density is 13,570
kg/m^3.
A. 99.45 kpa
B. 97.41 kpa
C. 95.44 Kpa
D. 98.66 Kpa
B. 97.41 kpa
127
An ideal gas at 0.80 atmosphere and
87degC occupies 0.450 liter. How
many moles are there is the sample?
(R=0.0821 liter-atm/mole-K)
A. 0.0002 mole
B. 0.0378 mole
C. 0.0122 mole
D. 0.0091 mole
C. 0.0122 mole
128
A certain gas at 101.325 Kpa and 10
degC whose volume is 2.83 m^3 are
compressed into a storage vessel of
0.31m^3 capacity. Before admission,
the storage vessel contained the gas
at a pressure and temperature of
137.8 Kpa and 26 degC; after
admission the pressure has increased
to 1171.8 Kpa. What should be the
fnal temperature of the gas in the
vessel in kelvin?
A. 298.0
B. 319.0
C. 180.0
D. 314.2
D. 314.2
129
A superheat steam Rankine cycle has
turbine inlet conditions of 17.5 MPa
and 530 degC expands in a turbine to
0.007 Mpa. The Turbine and pump
polytrophic efficiencies are 0.85 and
0.75 respectively, pressure losses
between pump and turbine inlet are 1.5 Mpa. What should be the pump
work in Kj/kg?
A. 17.34
B. 27.32
C. 25.32
D. 47.33
C. 25.32
130
In an open feedwater heater for a
steam plant, saturated steam at 7 bar
is mixed sub-cooled liquid at 7 bar and
25 degC. Just enough steam is
supplied to ensure that the mixed
steam leaving the heater will be
saturated liquid at 7 Bar when heater
efficiency is 95%. Calculate the mass
flow rate of sub-cooled liquid if steam
flow rate is 0.865 kg/s.
A. 2.725 kg/s
B. 3.356 kg/s
C. 2.869 kg/s
D. 3.948 kg/s
C. 2.869 kg/s
131
A steam condenser receives 10 kg/s of
steam with an enthalpy of 2770 kj/kg.
steam condenses into a liquid and
leaves with an enthalpy of 160 kj/kg.
cooling water passes through the
condenser with temperature increases
from 13 DegC to 24 DegC. Calculate
the water flow rate in Kg/s.
A. 583
B. 567
C. 523
D. 528
B. 567
132
Steam expands adiabatically in a
turbine from 200 Kpa, 400 DegC to
400 Kpa, 250 DegC. What is the
efectiveness of the process in percent
assuming an atmospheric pressure of
18 DegC. Neglect changes in kinetic
and potential energy.
A. 82
B. 84
C. 79.60
D. 79.46
D. 79.46
133
A heat exchanger was installed
purposely to cool 0.50 kg of gas per
second. Molecular weight is 32 and k
= 32. The gas is cooled from 150 degC
to 80 DegC. Water is available at the
rate of 0.30 kg/s and at a temperature
of 5 degC. Calculate the exit
temperature of the water in degC.
A. 44.86
B. 42.88
C. 46.45
D. 40.34
A. 44.86
134
A 350 mm x 450 mm steam engine
running at 280 rpm has an entrance
steam condition of 2 MPa and 230
degC and exit 0.1 Mpa. The steam
consumption is 2000 kg/hr and
mechanical efficiency is 85% if
indicated mean efective pressure is
600 Kpa, determine brake thermal
efficiency.
A. 23,34%
B. 15.25%
C. 14.16%
D. 27.34%
B. 15.25%
135
A steam turbine receives 5,000 kg/hr
of steam at 5 Mpa and 400 DegC and
velocity of 30 m/sec. It leaves the
turbine at 0.006 Mpa and 85% quality
and velocity of 15m/sec. radiation loss
is 10,000 Kj/hr. fnd the KW developed.
A. 1273.29
B. 2173.29
C. 1373.60
D. 7231.29
C. 1373.60
136
A steam turbine with 85% stage
efficiency receives steam at 7 Mpa and
550 degC and exhaust as 20 Kpa.
Determine the turbine work.
A. 1,117 Kj/kg
B. 1,182 kj/kg
C. 1,123.34 kj/kg
D. 1,054.95 Kj/kg
D. 1,054.95 Kj/kg
137
A steam turbine with 80% stage
efficiency receives steam at 7 Mpa and
550 DegC and exhaust as 20 Kpa,
determine the quality at exhaust.
A. 96.96%
B. 76.34%
C. 82.34%
D. 91.69%
A. 96.96%
138
18,000 KW geothermal plant has a
generator efficiency and turbine
efficiency of 90% and 80%,
respectively. The quality after
throttling is 20% and each well
discharges 400,000 kg/hr, determine
the number of wells are required to
produce if the change of enthalpy at
entrance and exit of turbine is 500
kj/kg.
A. 4 wells
B. 2 wells
C. 6 wells
D. 8 wells
B. 2 wells
139
A liquid dominated geothermal plant
with a single flash separator receives
water at 204 DegC. The separator
pressure is 1.04 Mpa. A direct contact
condenser operates at 0.034 Mpa. The
turbine has a Polytropic efficiency of
0.75 for a cycle output of 60 MW, what
is the mass flow rate if the wall-water
in kg/s?
A. 2,933
B. 2,100
C. 1,650
D. 2,444
A. 2,933
140
An empty, open can is 30 cm high,
with a 15 cm diameter. The can with
the open end down is pushed under
water with a density of 1000 kg/m^3.
Find the water level in the can when
the top of the can is 50 cm below the
surface.
A. 17.20 cm
B. 12.12 cm
C. 4.20 cm
D. 5.87 cm
B. 12.12 cm
141
A cylindrical pipe with water flowing
downward at 0.03 m^3/s having top
diameter of 0.08, bottom diameter of
0.04 m and height of 1.5 m. fnd the
pressure between the pipe.
A. 154.63 Kpa
B. 197.93 Kpa
C. 252.44 Kpa
D. 243.92 Kpa
C. 252.44 Kpa
142
Determine the size of pipe which will
deliver 8 liter of medium oil (c = 6.10
x 10 ^-6 m^2/s) assuming laminar
flow conditions
A. 622 mm
B. 754 mm
C. 950 mm
D. 835 mm
D. 835 mm
143
The type of flow occupying in a 1 cm
diameter pipe which water flows at a
velocity of 2.50m/s. Use v = 1.13 x
10^-6 m^2/s for water.
A. Turbulent
B. Constant
C. Laminar
D. None of these
A. Turbulent
144
What force is exerted by water jet 60
mm diameter if it strikes a wall at the
rate of 15 m/s?
A. 636.17 N
B. 442.62 N
C. 764.23 N
D. 563.34 N
A. 636.17 N
145
A 300 mm diameter pipe discharges
water at the rate of 200 li/s. point 1 on
the pipe has a pressure of 260 Kpa
and 3.4 m below point 1 is point 2 with
a pressure of 300 Kpa. Compute the
head loss between points 1 and 2.
A. 4.29 m
B. 2.59 m
C. 6.32 m
D. 1.87 m
D. 1.87 m
146
Water flowing at the rate of 10 m/s
from an orifce at the bottom of a
reservoir. Find the pressure at the
bottom of reservoir.
A. 30 Kpag
B. 40 Kpag
C. 50 Kpag
D. 60 Kpag
C. 50 Kpag
147
Steam flows through a nozzle at 400
deg. C and 1 Mpa (h = 3263.9 KJ/kg)
with velocity of 300 m/s. fnd the
stagnation enthalpy.
A. 3300 KJ/kg
B. 3290 KJ/kg
C. 3320 KJ/kg
D. 3309 KJ/kg
D. 3309 KJ/kg
148
Air flows through a nozzle at a speed
of 350 m/s. Find the stagnation
temperature if entrance temperature
is 200 deg. C
A. 241.25 deg. C
B. 251.25 deg. C
C. 261.25 deg C
D. 271.25 deg. C
C. 261.25 deg C
149
Carbon dioxide flows through a nozzle
with a speed of 400 m/s. Compute the
dynamic temperature.
A. 92.56 K
B. 94.56 K
C. 96.56 K
D. 98.56 K
B. 94.56 K
150
Carbon dioxide flows through a nozzle
with a speed of 380 m/s. The entrance condition of nozzle is 250 deg. C and
1200 Kpa. Find the stagnation
pressure.
A. 2,136.34 Kpa
B. 2,146.34 Kpa
C. 2,156.34 Kpa
D. 2,166.34 Kpa
A. 2,136.34 Kpa
151
Air enters a difuser with a velocity of
200 m/s. determine the velocity of
sound if air temperature is 30 deg. C
A. 349 m/s
B. 359 m/s
C. 369 m/s
D. 379 m/s
C. 369 m/s
152
Air flows through a nozzle with
temperature of entrance of 420 deg. K
stagnation temperature of 468 deg. K.
fnd the mach number.
A. 0.744
B. 0.754
C. 0.764
D. 0.774
B. 0.754
153
Air at 300 deg. K and 200 Kpa is
heated at constant pressure to 600
deg. K. determine the change of
internal energy.
A. 245.58 KJ/kg
B. 235.58 KJ/kg
C. 225.58 KJ/kg
D. 215.58 KJ/kg
D. 215.58 KJ/kg
154
An insulated rigid tank initially
contains 1.5 lb of helium at 60 deg F
and 50 psia. A paddle wheel with
power rating of 0.02 hp is operated
within the tank for 30 min. Determine
the fnal temperature.
A. 159.22 deg. F
B. 169.22 deg. F
C. 179.22 deg. F
D. 189.22 deg. F
C. 179.22 deg. F
155
A 4 m^2 asphalt pavement with
emissivity of m0.85 has a surface
temperature of 50 deg. C. Find the
maximum rate of radiation that can be
emitted from the surface.
A. 2,068.32 watts
B. 2,078.32 watts
C. 2,088.32 watts
D. 2,098.32 watts
D. 2,098.32 watts
156
An aluminum pan whose thermal
conductivity is 237 W/m-C has a flat
bottom whose diameter is 20 cm and
thickness 0.4 cm. heat is transferred
steadily to boiling water in the pan
through its bottom at a rate of 500
watts. If the inner surface of the
bottom of the pan is 105 deg. C,
determine the temperature of the
surface of the bottom of the pan
A. 95.37 deg. C
B. 105.27 deg. C
C. 115. 27 deg. C
D. 125.27 deg. C
B. 105.27 deg. C
157
For a heat transfer purposes, a
standing man can be modeled as a 30
cm diameter, 170 cm long vertical
cylinder with both the top and bottom
surfaces insulated and with the side
surface at an average temperature of
34 deg. C. for convection heat transfer
coefficient of 15 W/m^2-C, determine
the rate of heat loss from this man by
convection in an environment at 20
deg. C.
A. 316.46 watts
B. 326.46 watts
C. 336.46 watts
D. 346.46 watts
C. 336.46 watts
158
A 5 cm diameter spherical ball whose
surface is maintained at a
temperature of 70 deg. C is suspended
in the middle of a room at 20 deg. C. if
the convection heat transfer
coefficient is 15 W/m^2-C and the
emissitivity of the surface is 0.8,
determine the total heat transfer from
the ball.
A. 23.56 watts
B. 32.77 watts
C. 9.22 watts
D. 43.45 watts
B. 32.77 watts
159
A frictionless piston-cylinder device and a rigid tank contain 1.2 kmol of ideal gas at the same temperature, pressure and volume. Now heat is transferred, and the temperature of both system is raised by 15 deg. C. the amount of extra heat that must be
supplied to the gas in the cylinder that is maintained at constant pressure.
A. 0
B. 50 KJ
C. 100 KJ
D. 150 KJ
D. 150 KJ
160
A supply of 50 kg of chicken at 6 degC contained in a box is to be frozen to -16 degC in a freezer. Determine the amount of heat that needs to be removed. The latent heat of the chicken is 247 kj/kg and its specifc heat is 32 kj/kg-C above freezing and 1.77 Kj/kg-C below freezing. The container box is 5 kg and the specifc heat of the box material is 1.4 kj/kg-C. also the freezing temperature of chicken is -2.8 C.
A. 15,206.4 KJ
B. 50.5 KJ
C. 15,156 KJ
D. 1,863 KJ
A. 15,206.4 KJ
161
