Specific heat of air at constant pressure is equal to
 (a) 0.17
 (b) 0.21
 (c) 0.24
 (d) 1.0
 (e) 1.41

1 Answer

Answer :

Answer : c

Related questions

Description : The ratio of two specific heats of air is equal to  (a) 0.17  (b) 0.24  (c) 0.1  (d) 1.41  (e) 2.71.

Last Answer : Answer : d

Description : Universal gas constant is defined as equal to product of the molecular weight of the gas and  (a) specific heat at constant pressure  (b) specific heat at constant volume  (c) ratio of two specific heats  (d) gas constant  (e) unity.

Last Answer : Answer : d

Description : The value of specific heat at constant pressure (cp) is __________ that of at constant volume (cv).  A. less than  B. equal to  C. more than

Last Answer : Answer: C

Description : The ratio of specific heat at constant pressure (Cp) and specific heat at constant volume (cv) is  A. equal to one  B. less than one  C. greater than one  D. none of these

Last Answer : Answer: C

Description : According to Avogadro's Hypothesis  (a) the molecular weights of all the perfect gases occupy the same volume under same conditions of pressure and temperature  (b) the sum of partial pressure of ... gases have two values of specific heat  (e) all systems can be regarded as closed systems.

Last Answer : Answer : a

Description : The volume of a confined gas is held constant, the pressure is directly proportional to the absolute temperature.  a. Charle’s Law  b. Boyle’s Law  c. Joule’s Law  d. Specific Heat

Last Answer : Boyle’s Law

Description : From the steam table, determine the average constant pressure specific heat (c) of steam at 10 kPa and45.8 ˚C  A.1.79 kJ/ kg-˚C  B.10.28 kJ/ kg-˚C  C.30.57 kJ/ kg-˚C  D. 100.1 kJ/ kg-˚C Formula: h = c T ∆ ∆ From the steam table At 47.7 ˚C h= 2588.1 kJ/ kg At 43.8 ˚C h= 2581.1 kJ/ kg

Last Answer : 1.79 kJ/ kg-˚C

Description : The heat supplied to the gaS at constant volume is (where m = Mass of gas, cv = Specific heat at constant volume, cp = Specific heat at constant pressure, T2 – T1 = Rise in temperature, and R = Gas constant)  A. mR(T2 – T1)  B. mcv(T2 – T1)  C. mcp(T2 – T1)  D. mcp(T2 + T1)

Last Answer : Answer: B

Description : The specific heat at constant volume is  A. the amount of heat required to raise the temperature of unit mass of gas through one degree, at constant pressure  B. the amount of heat required to raise ... to raise the temperature of 1 kg of water through one degree  D. any one of the above

Last Answer : Answer: B

Description : The amount of heat required to raise the temperature of the unit mass of gas through one degree at constant volume, is called  A.specific heat at constant volume  B.specific heat at constant pressure  C.kilo Joule  D.none of these

Last Answer : Answer: A

Description : Change in internal energy in a closed system is equal to heat transferred if the reversible process takes place at constant  (a) pressure  (b) temperature  (c) volume  (d) internal energy  (e) entropy.

Last Answer : Answer : c

Description : Change in enthalpy in a closed system is equal to heat transferred if the reversible process takes place at constant  (a) pressure  (b) temperature  (c) volume  (d) internal energy  (e) entropy.

Last Answer : Answer : a

Description : The specific heat of air increases with increase in  (a) temperature  (b) pressure  (c) both pressure and temperature  (d) variation of its constituents  (e) air flow

Last Answer : Answer : a

Description : A unit of pressure used in high vacuum technology, which is equal to 1mmhg.  a. specific heat  b. isometric  c. isobaric  d. torr

Last Answer : torr

Description : Which law states that the specific heat of a gas remains constant at all temperatures and pressures  (a) Charles’ Law  (b) Joule’s Law  (c) Regnault’s Law  (d) Boyle’s Law  (e) there is no such law.

Last Answer : Answer : c

Description : Molecular volume of any perfect gas at 600 x 103 N/m2 and 27°C will be  (a) 4.17m3/kgmol  (b) 400 m3/kg mol  (c) 0.15 m3/kg mol  (d) 41.7 m3/kg mol  (e) 417m3/kgmol.

Last Answer : Answer : a

Description : Gas being heated at constant volume is undergoing the process of.  a. isometric  b. specific heat  c. enthalpy  d. isothermal

Last Answer : isometric

Description : _____ is that property of a substance which remains constant if no heat enters or leaves the substance, while it does work or alters its volume, but which increases or diminishes should a small amount of heat enter or leave.  a. Entrophy  b. Enthalpy  c. Specific Heat  d. None of the above

Last Answer : Entrophy

Description : Which of the following parameters is constant for a mole for most of the gases at a given temperature and pressure  (a) enthalpy  (b) volume  (c) mass  (d) entropy  (e) specific volume.

Last Answer : Answer : b

Description : Twenty grams of ice at 0˚C melts to water at 0˚C. How much does the entropy of the 20g change in this process?  a. 30.5 J/K  b. 24.6 J/K  c. 21.3 J/K  d. 15.7 J/K

Last Answer : 24.6 J/K

Description : The gas constant (R) is equal to the __________ of two specific heats.  A. sum  B. difference  C. product  D. ratio

Last Answer : Answer: B

Description : While swimming a depth of 13m in a fresh water lake a fish emits an air bubble of volume 2 mm² atmospheric pressure is 100kpa 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

Last Answer : 217.17 kpa

Description : Which of the following is not the intensive property  (a) pressure  (b) temperature  (c) density  (d) heat  (e) specific volume.

Last Answer : Answer : d

Description : Which of the following quantities is not the property of the system  (a) pressure  (b) temperature  (c) specific volume  (d) heat  (e) density.

Last Answer : Answer : d

Description : According to kinetic theory of gases, the absolute zero temperature is attained when  (a) volume of the gas is zero  (b) pressure of the gas is zero  (c) kinetic energy of the molecules is zero  (d) specific heat of gas is zero  (e) mass is zero.

Last Answer : Answer : c

Description : What is constant for a substance that is considered “incompressible”?  A. Specific volume of density  B. Pressure  C. Temperature  D. All of the above

Last Answer : Specific volume of density

Description : In a Carnot cycle, heat is transferred at  (a) constant pressure  (b) constant volume  (c) constant temperature  (d) constant enthaply  (e) any one of the above.

Last Answer : Answer : c

Description : Addition of heat at constant pressure to a gas results in  (a) raising its temperature  (b) raising its pressure  (c) raising its volume  (d) raising its temperature and doing external work  (e) doing external work.

Last Answer : Answer : d

Description : Change in enthalpy of a system is the heat supplied at  (a) constant pressure  (b) constant temperature  (c) constant volume  (d) constant entropy  (e) N.T.P. condition.

Last Answer : Answer : a

Description : A heat exchange process in which the product of pressure and volume remains constant is known as  (a) heat exchange process  (b) throttling process  (c) isentropic process  (d) adiabatic process  (e) hyperbolic process.

Last Answer : Answer : e

Description : Ten cu ft. of air at 300 psia 400°F is cooled to 140°F at constant volume. What is the final pressure? (formula: p2 = p1T2/T1)  a. 0  b. 209 psia  c. - 420 psia  d. None of the above

Last Answer : 209 psia

Description : According to first law of thermodynamics  (a) work done by a system is equal to heat transferred by the system  (b) total internal energy of a system during a process remains constant  ( ... , enthalpy and entropy during a process remain constant  (d) total energy of a system remains constant

Last Answer : Answer : d

Description : If a gas is heated against a pressure, keeping the volume constant, then work done will be equal to  (a) + v  (b) – ve  (c) zero  (d) pressure x volume  (e) any where between zero and infinity.

Last Answer : Answer : c

Description : Is the force of gravity on unit volume?  a. Specific Weight  b. Specific Heat  c. Specific Pressure  d. Specific Volume

Last Answer : Specific Weight

Description : Sum of the internal energy of a substance and the product of pressure and volume.  a. Specific Heat  b. Specific Gravity  c. Isolated System  d. Enthalpy

Last Answer : Enthalpy

Description : What predicts the approximate molar specific heat at high temperatures from the atomic weight?  A. Third law of thermodynamics  B. Law of Dulong and Petit  C. Mollier diagram  D. Pressure-enthalpy diagram

Last Answer : Law of Dulong and Petit

Description : A problem Drum ( 3 ft. diameter ; 6 ft. height ) is field with a fluid whose density is 50 lb/ft^3. Determine the total volume of the fluid.  A. 42.41 ft^3  B.44.35 ft^3  C.45.63 ft^3  D.41.23 ft^3 Formula: Vf = (pi d^2 h) / 4

Last Answer : 42.41 ft^3

Description : Ten cu. ft of air at 300psia and 400°F is cooled to 140°F at constant volume. What is the transferred heat?  a.-120Btu  b. -220Btu  c.-320Btu  d. -420Btu formula: Q= mcv(T2-T1)

Last Answer : -420Btu

Description : Is a steady flow process at total constant pressure through a control volume for which there is no heat?  a. Adiabatic Saturation Process  b. Dew point  c. Adiabatic Ratio  d. None of the above

Last Answer : Adiabatic Saturation Process

Description : As we heat a gas at constant pressure, its volume  a. increases  b. decreases  c. stays the same  d. none of the above

Last Answer : increases

Description : On volume basis, air contains following parts of oxygen  (a) 21  (b) 23  (c) 25  (d) 77  (e) 79.

Last Answer : Answer : a

Description : On weight basis, air contains following parts of oxygen  (a) 21  (b) 23  (c) 25  (d) 73  (e) 79.

Last Answer : Answer : b

Description : According to Avogadro's law  A. the product of the gas constant and the molecular mass of an ideal gas is constant  B. the sum of partial pressure of the mixture of two gases is sum of the ... all gases, at the same temperature and pressure, contain equal number of molecules  D. all of the above

Last Answer : Answer: C

Description : If air is at pressure, p, of 3200 lbf/ft2 , and at a temperature, T, of 800 ˚R, what is the specific volume, v? (R=5303 ft-lbf/lbm-˚R, and air can be modeled as an ideal gas.)  A.9.8 ft^3/lbm  B.11.2 ft^3/lbm  C.13.33 ft^3/lbm  D.14.2 ft^3/lbm Formula: pv = RT v = RT / p

Last Answer : 13.33 ft^3/lbm

Description : Water (specific heat cv= 4.2 kJ/ kg ∙ K ) is being heated by a 1500 W h eater. What is the rate of change in temperature of 1kg of the water?  A. 0.043 K/s  B. 0.179 K/s  C. 0.357 K/s  D. 1.50 K/s Formula: Q = mcv ( T)

Last Answer : 0.179 K/s

Description : What is the resulting pressure when one pound of air at 15 psia and 200 ˚F is heated at constant volume to 800 ˚F?  A.15 psia  B. 28.6 psia  C. 36.4 psia.  D. 52.1 psia Formula : T1/p1 = T2/p2 p2= p1T2 / T1

Last Answer : 28.6 psia

Description : _________ is the temperature to which the air must be cooled, at constant pressure, to produce saturation.  a. relative humidity  b. triple point temperature  c. dew point  d. critical point

Last Answer : dew point

Description : On a day when the partial pressure of water vapor remains constant, what happens as the temperature rises?  a. the relative humidity increases  b. the relative humidity decreases  c. the relative humidity remains constant  d. the air would eventually become saturated

Last Answer : the relative humidity decreases

Description : 3.0 lbm of air are contained at 25 psia and 100 ˚F. Given that Rair = 53.35 ft-lbf/lbm- ˚F, what is the volume of the container?  A.10.7 ft^3  B.14.7 ft^3  C.15 ft^3  D.24.9 ft^3 Formula: use the ideal gas law pV = mRT T = (100 +460) ˚R V = mRT/p

Last Answer : 24.9 ft^3

Description : A simple steam engine receives steam from the boiler at 180˚C and exhausts directly into the air at 100˚C. What is the upper limit of its efficiency?  a. 11.28 %  b. 36.77 %  c. 20.36 %  d. 17.66 %

Last Answer : 17.66 %