This is the Multiple Choice Questions Part 8 of the Series in Thermodynamics as one of the General Engineering and Applied Sciences (GEAS) topics. In Preparation for the ECE Board Exam make sure to expose yourself and familiarize yourself with each and every questionย compiled here taken from various sources including past Board Questions in General Engineering and Applied Sciences (GEAS) field, Thermodynamics Books, Journals, and other Thermodynamics References.
Continue Practice Exam Test Questions Part 8 of the Series
โ MCQ in Thermodynamics Part 7 | ECE Board Exam
Choose the letter of the best answer in each question.
351. A bayabas falls from a branch 5 m above the ground with what speed in meter per second does it strike the ground assume g = 10m/sยฒ.
A. 11 m/s
B. 12 m/s
C. 13 m/s
D. 10 m/s
โฒKE = mV2/2gc
Answer: Option D
Explanation:
352. While swimming at a depth of 13 m in a freshwater lake a fish emits an air bubble of volume 2 mmยฒ atmospheric pressure is 100 kpa what is the original pressure of the bubble.
A. 217.17 kpa
B. 119 kpa
C. 326.15 kpa
D. 210 kap
Pabs = Pg + Patm
Answer: Option A
Explanation:
353. Oxygen at 15ยฐC and 10.3 Mpa gauge pressure occupies 600 L. What is the occupied by the oxygen at 8.28 Mpa gauge pressure and 35ยฐC?
A. 789.32 L
B. 796.32 L
C. 699 L
D. 588 L
V2= P1V1/T1P2
Answer: Option B
Explanation:
354. Water is flowing through a 1 foot diameter pipe at the rate of 10ft/sec. What is the volume flow rate of water in ftยณ/sec?
A. 7.85
B. 6.85
C. 8.85
D. 5.85
V = Aฮฝ
Answer: Option A
Explanation:
355. A certain fluid is flowing in a 0.5 m x 0.3 channel at the rate of 3 m/s and has a specific volume of 0.012 mยณ/kg. Determined the mass of water flowing in kg/s.
A. 267 kg/s
B. 378 kg/s
C. 375 kg/s
D. 456.5 kg/s
m = Aฮฝ/V
Answer: Option C
Explanation:
356. A gas having a volume of100 ftยณ at 27ยฐC is expanded to 120 ftยณ by heated at constant pressure to what temperature has it been heated to have this new volume?ย
A. 87ยฐC
B. 85ยฐC
C. 76ยฐC
D. 97ยฐC
t2= T2โT1
Answer: Option A
Explanation:
357. Water flow to a terminal 3 mm diameter and has an average speed of 2 m/s. What is the rate of flow in cubic meter/mm?
A. 0.0001mยณ/min
B. 0.076 mยณ/min
C. 0.085 mยณ/min
D. 0.097 mยณ/min
Answer: Option C
Explanation:
358. Water flowing at a 6m/s through a 60 mm pipe is suddenly channeled into a 30 mm pipe. What is the velocity in the small pipe?
A. 34 m/s
B. 24 m/s
C. 15 m/s
D. 27 m/s
Answer: Option B
Explanation:
359. A vertical column of water will be supported to what height by standard atmospheric pressure.
A. 33.9 ft
B. 45 ft
C. 67 ft
D. 25.46 ft
ho= Po/Yo
Answer: Option A
Explanation:
360. A fluid flows in a steady manner between two section in a flow line at section 1: A 1 = 1 ftยฒ, V1 = 100 fpm, volume1 of 4 ftยณ/lB. at sec2: A2 = 2 ftยฒ, p= 0.20 lb/ftยณ calculate the velocity at section 2.
A. 625 fpm
B. 567 fpm
C. 356 fpm
D. None of the above
Answer: Option A
Explanation:
361. The weight of an object is 50 lB. What is its mass at standard condition?
A. 50 lbm
B. 60 lbm
C. 70 lbm
D. 80 lbm
formula: m = Fgk /g
Answer: Option A
Explanation:
362. A vertical column of water will be supported to what height by standard atmospheric pressure. If the Y w = 62.4 lb/ft3 po = 14.7 psi.
A. 44.9 ft
B. 33.9 ft
C. 22.9 ft
D. 55.9 ft
formula: ho= po/Yw
Answer: Option B
Explanation:
363. For a certain gas R = 320 J/kg.K and cv= 0.84 kJ/kg.K. Find k?
A. 1.36
B. 1.37
C. 1.38
D. 1.39
formula: k= R / cv+1
Answer: Option C
Explanation:
364. Ten cu. ft of air at 300 psia and 400ยฐF is cooled to 140ยฐF at constant volume. What is the transferred heat?
A.-120 Btu
B. -220 Btu
C.-320 Btu
D. -420 Btu
formula: Q= mcv(T2-T1)
Answer: Option D
Explanation:
365. Utilizing the answer to the previous problem, estimate the overall or average increase in temperature ( ฮT) of the concrete roof from the energy absorbed from the sun during a 12 hour day. Assume that all of the radiation absorbed goes into heating the roof. The specific heat of concrete is about 900 J/kg, and the density is about 2,300 kg/m3.
A. 7.9ยฐC
B. 8.9ยฐC
C. 9.9ยฐC
D. 10.9ยฐC
formula: ฮQ = m c ฮT
Answer: Option A
Explanation:
366. The concrete roof of a house is 10 m by 8 m and 10 cm thick (4″). Estimate the total heat the roof would absorb over the 12 day?
A. 1.3 x 108 J
b 2.3 x 108 J
C. 3.3 x 108 J
D. 4.3 x 108 J
formula: ฮQ = ฮQ/ฮtx ฮt
Answer: Option A
Explanation:
367. The value for the ฮU of a system is -120 J. If the system is known to have absorbed 420 J of heat, how much work was done?
A. -540 J
B. -640 J
C. -740 J
D. -840 J
formula: ฮU = q +w
Answer: Option A
Explanation:
368. When the pressure on a 1 kg liquid is increased isothermally from 1 bar to 3000 bar the Gibbs free energy increases by 360 kJ. Estimate the density of the liquid.
A. 0.66 kg liter-1
B. 0.77 kg liter-1
C. 0.88 kg liter-1
D. 0.99 kg liter-1
Answer: Option B
Explanation:
369. A car whose mass is 2 metric tons is accelerated uniformly from stand hill to 100 kmph in 5 sec. Find the driving force in Newtonโs.
A. 11,120 N
B. 11,320 N
C. 11,420 N
D. 11520 N
formula: F= ma / k
Answer: Option A
Explanation:
370. An ideal gas of volume 1liter and pressure 10 bar undergoes a quasi static adiabatic expansion until the pressure drops to 1 bar. Assume ฮณ to be 1.4 what is the final volume?
A. 3.18 l
B. 4.18 l
C. 5.18 l
D. 6.18 l
Answer: Option C
Explanation:
371. Two masses, one of the 10 kg and the other unknown, are placed on a scale in a region where g = 9.67 m/sec2. The combined weight of these two masses is 174.06 N. Find the unknown mass in kg.
A. 20 kg
B. 19 kg
C. 18 kg
D. 17 kg
formula: m=Fg k / g
Answer: Option C
Explanation:
372. The flow energy of 5 ft3 of a fluid passing a boundary to a system is 80,000 ft-lB. Determine the pressure at this point.
A. 222 psi
B. 333 psi
C. 444 psi
D. 111 psi
formula: Ef= pV
Answer: Option D
Explanation:
373. Find ะธ for steam at 100 psia and 600ยฐF. If h = 1329.6 and v = 6.216
A. 1214 Btu/lb
B. 1234 Btu/lb
C. 1342 Btu/lb
D. 1324 Btu/lb
formula: ะธ = hโ pv/ J
Answer: Option A
Explanation:
374. What mass of nitrogen is contained in a10 ft3 vessel at a pressure of 840atm and 820ยฐR? Make a computation by using ideal gas equation.
A. 194 lb
B. 214 lb
C. 394 lb
D. 413 lb
formula: m=pV /RT
Answer: Option C
Explanation:
375. A rotary compressor receives 6 m3/ min of a gas(R=410J/ kgK, cp=1.03kJ /kgK,k= 1.67) at 105 k/Paa, 27ยฐC and delivers it at 630 kPaa: ฮP = 0, ฮK= 0. Find the work if the process is isentropic?
A. โ1664 kJ/min
B. โ1774 kJ/min
C. โ1884 kJ/min
D. โ1994 kJ/min
formula: WSF = Q- ฮH m=p1V1/RT1 T2= T1(p2/p1)(k-1)/k
Answer: Option A
Explanation:
376. A carnot power cycle operates on 2 lb of air between the limits of 71ยฐF and 500ยฐF. The pressure at the beginning of isothermal expansion is 400 psia and at the end of isothermal expansion is 185 psig. Determine the volume at the end of isothermal compression.
A. 7.849 ft3
B. 7.850 ft3
C. 7.851 ft3
D. 7852 ft3
formula: V= mRT/ P P3= P2[T3/ T2]
Answer: Option A
Explanation:
377. During a polytropic process,10lb of an ideal gas, whose R= 40 ft.lb/lB.R and cp = 0.25 Btu/lB.R, changes state from 20 psia and 40ยฐF to 120psia and 340ยฐF. Determine n?
A. 1.234
B. 1.345
C. 1.456
D. 1.356
formula: [ p2/p1]n-1 / n = T2/T1
Answer: Option D
Explanation:
378. A perfect gas has a value of R= 319.2 J/ kf.K and k= 1.26. If 120 kJ are added to 2.27 kfg of this gas at constant pressure when the initial temp is 32.2ยฐC? Find T2.
A. 339.4 K
B. 449.4 K
C. 559.4K
D. 669.4K
formula: cp = kR/ k-1 Q= mcp(T2-T1)
Answer: Option A
Explanation:
379. A certain gas, with cp = 0.529 Btu/ lB. ยฐRand R = 96.2 ft.lb/lB. ยฐR, expands from 5 cu ft and 80ยฐF to 15 cu ft while the pressure remains constant at 15.5 psiA. Compute for T2.
A.1520ยฐR
B. 1620ยฐR
C. 1720ยฐR
D. 1820ยฐR
formula: T2= T1V2/V1
Answer: Option B
Explanation:
380. A System has a temperature of 250ยฐF. Convert this Value to ยฐR?
A. 740ยฐR
B.730ยฐR
C. 720ยฐR
D. 710ยฐR
formula: ยฐR= ยฐF + 460
Answer: Option D
Explanation:
381. Steam with a specific volume of 0.09596 mยณ/kg undergoes a constant pressure process at 1.70 MPa until the specific volume becomes 0.13796 mยณ/kg. What are (A. the final temperature, (B. โu, (C. W, (D.โs, and (e) Q?
A. 265.4ยฐC, 430.7kJ/kg, 71.4kJ/kg, 1.0327kJ/(kg)(K),502.1 kJ/kg
B. 204.2ยฐC, -703.2 kJ/kg, -84.15 kJ/kg, -1.7505 kJ/(kg)(K), -787.4 kJ/kg
C. 304.2ยฐC, -803.2 kJ/kg, -89.15 kJ/kg, -2.7505 kJ/(kg)(K), -987.4 kJ/kg
D. 279.4ยฐC, 439.7kJ/kg, 79.4kJ/kg, 3.0327kJ/(kg)(K),602.1 kJ/kg
Answer: Option A
Explanation:
382. Steam with an enthalpy of 2843.5 kJ/kg undergoes a constant pressure process at 0.9 MPa until the enthalpy becomes 2056.1 kJ/kg. What are (A. the initial temperature or quality, (B. โu, (C.W, (D. โs, and(e) Q?
A. 265.4ยฐC, 430.7kJ/kg, 71.4kJ/kg, 1.0327kJ/(kg)(K),502.1 kJ/kg
B. 204.2ยฐC, -703.2 kJ/kg, -84.15 kJ/kg, -1.7505 kJ/(kg)(K),-787.4 kJ/kg
C. 304.2ยฐC, -803.2 kJ/kg, -89.15 kJ/kg, -2.7505 kJ/(kg)(K), -987.4 kJ/kg
D. 279.4ยฐC, 439.7kJ/kg, 79.4kJ/kg, 3.0327kJ/(kg)(K), 602.1 kJ/kg
Formula of #1and #2: โu = u2 โu1, W = p(v2-v1), โs =s2-s1, Q = h2 โh1
Answer: Option B
Explanation:
383. At throttling calorimeter receives steam from a boiler drum at0.11 MPa and is superheated by 10 degrees. If the boiler drum pressure is 1.55 MPa, what is the quality of the steam generated by the boiler?
A. 95.20%
B. 70.10%
C. 65.60%
D. 95.56%
Formula: h1 = hf1 + x1hfg1
Answer: Option A
Explanation:
384. A steam calorimeter receives steam from a pipe at 0.1 MPa and 20ยฐSH. For a pipe steam pressure of 2 MPa, what is the quality of the steam?
A. 95.56%
B. 70.10%
C. 95.20%
D. 85.10%
Formula: h1 = hf1 + x1hfg1
Answer: Option A
Explanation:
385. A 1-kg steam-water mixture at 1.0 MPa is contained in an inflexible tank. Heat is added until the pressure rises to 3.5 MPa and the temperature to 400ยฐ. Determine the heat added.
A. 1378.7 kJ
B. 1348.5 kJ
C. 1278,7 kJ
D. 1246,5 kJ
Formula: Q = (h2 โ p2v2) โ(h1 โp1v1)
Answer: Option A
Explanation:
386. Water vapor at 100 KPa and 150ยฐC is compressed isothermally until half the vapor has condensed. How much work must be performed on the steam in this compression process per kilogram?
A. -1384.7 kJ
B. 1384.7 kJ
C. -2384.7 kJ
D. 2384.7 kJ
Answer: Option A
Explanation:
387. Wet steam at 1 MPa flowing through a pipe is throttled to a pressure of 0.1 MPA. If the throttling temperature is110ยฐC, What is the quality of the steam in the pipe?
A. 96%
B. 86%
C. 76%
D. 66%
Answer: Option A
Explanation:
388. Steam is throttled to 0.1 MPa with 20 degrees of superheat. (A. What is the quality of throttled steam if its pressure is 0.75 MPa (B. What is the enthalpy of the process?
A. 97.6%,2713 kJ/kg
B. -97.6%, 2713 kJ/kg
C. 87.6%,3713 kJ/kg
D. -87.6%, 3713 kJ/kg
Answer: Option A
Explanation:
389. The pressure gauge on a 2000 mยณ tank of oxygen gas reads 600 kPA. How much volumes will the oxygen occupied at pressure of the outside air 100 kPa?
A. 14026.5 mยณ
B. 15026.5 mยณ
C. 13026.5 mยณ
D. 16026.5 mยณ
Formula: P1V1/T1 =P2V2/T2
Answer: Option A
Explanation:
390. Assuming compression is according to the Law PV = C, Calculate the initial volume of the gas at a pressure of 2 bars w/c will occupy a volume of 6mยณ when it is compressed to a pressure of 42 Bars.
A. 130mยณ
B. 136mยณ
C. 120mยณ
D. 126mยณ
Formula: P1V1/T1 =P2V2/T2
Answer: Option D
Explanation:
391. A Gas tank registers1000 kPA. After some gas has been used, the gauge registers 500 kPA. What percent of the gas remains in the tank?
A. 64.40%
B. 74.60%
C. 58.40%
D. 54.60%
Formula: Pabs = Patm + Pgage & %= P2/P1 * 100%
Answer: Option D
Explanation:
392. The volume of a gas under standard atmospheric pressure & 76 cmHg is 200mยณ. What is the volume when pressure is 80 cmHg if the temperature is unchanged?
A. 180 inยณ
B. 170 inยณ
C. 160 inยณ
D. 190 inยณ
Formula: P2V2 = P1V1
Answer: Option D
Explanation:
393. While swimming at depth of 120 m in a fresh water lake, A fish emits an air bubbles of volume 2.0 mmยณ atmospheric pressure is 100 kPA. What is the pressure of the bubble?
A. 217.7 kPa
B. 317.7 kPa
C. 417.7 kPa
D. 517.7 kPa
Formula: P= ฮดh
Answer: Option A
Explanation:
394. How many joules of work is the equivalent of 15000 cal of heat?
A. 62850 joules
B. 3579.95 joules
C. 14995.81 joules
D. 15004.19 joules
Formula: J =Work/Heat
J = mechanical equivalent of heat whose value is 4.19 joules/calorie
Answer: Option A
Explanation:
395. Two thick slices of bread, when completely oxidized by the body, can supply 200,000 cal of heat. How much work is this equivalent to?
A. 4,190,000 joules
B. 8,390,000 joules
C. 839,000 joules
D. 419 000 joules
Formula: J =Work/Heat
J = mechanical equivalent of heat whose value is 4.19 joules/calorie
Answer: Option D
Explanation:
396. 3 horsepower (hp) = _____________watts?
A. 1492 watts
B. 2238 watts
C. 746 watts
D. 2238 kilowatts
Formula: 1hp= 746 watts
Answer: Option B
Explanation:
397. How many Newtonโs (N) in 900,000 dynes?
A. 8 Newtonโs
B. 9 Newtonโs
C. 7 Newtonโs
D. 6 Newtonโs
Formula: 1Newton (N)=100,000dynes
Answer: Option B
Explanation:
398. Calculate the power output in horsepower of an 80-kg man that climbs a flight of stairs 3.8 m high in 4.0 s.
A. 744.8 hp
B. 0.998 hp
C. 746 hp
D. 1.998 hp
Formula: Power = Fd/t = mgh/t
F = W = mg
d = h
Answer: Option B
Explanation:
399. How many calories of heat will be needed to raise the temperature of 200 g of iron from 27ยฐC to 80ยฐC? (c = 0.11 cal/g. ยฐC.
A. 1.16 kcal
B. 2166 cal
C. 3.16 kcal
D. 4166 cal
Formula: H = mcโT
Answer: Option A
Explanation:
400. 100g of iron was heated to 100ยฐC and mixed with 22g of water at 40ยฐC. The final temperature of the mixture was 60ยฐC. Show that the heat given off by the iron equals the heat absorbed by the water.
A. 440 cal
B. 540 cal
C. 340 cal
D. 640 cal
Formula: H (given off by iron) = H (absorbed by water),
mcโT(iron)= mcโT(water)
Answer: Option A
Explanation:
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Complete List of MCQs in General Engineering and Applied Science per topic
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