y = specific heat ratio of an ideal gas is equal to
(A) Cp/Cv
(B) Cp/(CP-R)
(C) 1 + (R/CV)
(D) All (A), (B) and (C)

1 Answer

Answer :

D) All (A), (B) and (C)

Related questions

Description : Air enters an adiabatic compressor at 300K. The exit temperature for a compression ratio of 3, assuming air to be an ideal gas (Y = Cp/Cv = 7/5) and the process to be reversible, is (A) 300 × (32/7) (B) 300 × (33/5) (C) 300 × (333/7) (D) 300 × (35/7)

Last Answer : A) 300 × (32/7)

Description : Velocity of a gas in sound is not proportional to (where, T = Absolute temperature of the gas. P = Absolute pressure of the gas. y = Ratio of specific heats (Cp/Cv) ρ = specific weight of the gas) (A) √T (B) 1/√P (C) √y (D) 1/√ρ

Last Answer : (B) 1/√P

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 equation, Cp- Cv = R, is true for __________ gas. (A) No (B) Any real (C) Only ideal (D) Both (B) and (C)

Last Answer : (C) Only ideal

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 : On a P-V diagram of an ideal gas, suppose a reversible adiabatic line intersects a reversible isothermal line at point A. Then at a point A, the slope of the reversible adiabatic line (∂P/∂V)s and the slope of the reversible isothermal line ... Y (C) (∂P/∂V)S = y(∂P/∂V)T (D) (∂P/∂V)S = 1/y(∂P/∂V)T

Last Answer : (C) (∂P/∂V)S = y(∂P/∂V)T

Description : Cp- Cv = R is valid for __________ gases. (A) Ideal (B) Very high pressure (C) Very low temperature (D) All of the above

Last Answer : (A) Ideal

Description : For perfect gas a. cp – cv = R b. cp + cv = R c. cp / cv = R d. cp X cv = R Where cp & cv are specific heats at constant pressure and volume.

Last Answer : ANSWER a. CP – CV = R

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 : Equal volumes of two monoatomic gases, A and B, at same temperature and pressure are mixed. The ratio of specific heats (Cp /Cv ) of the mixture will be (1) 1.67 (2) 0.83 (3) 1.50 (4) 3.3

Last Answer : (1) 1.67

Description : In a P-V diagram (for an ideal gas), an isothermal curve will coincide within adiabatic curve (through a point), when (A) Cp < Cv (B) Cp = Cv (C) Cp > Cv (D) C ≥ Cv

Last Answer : (B) Cp = Cv

Description : (1/V) (∂V/∂T)Pis the mathematical expression (A) Joule-Thomson co-efficient (B) Specific heat at constant pressure (Cp) (C) co-efficient of thermal expansion (D) Specific heat at constant volume (CV)

Last Answer : (C) co-efficient of thermal expansion

Description : (∂T/∂P)H is the mathematical expression for (A) Specific heat at constant pressure (Cp) (B) Specific heat at constant volume (Cv) (C) Joule-Thompson co-efficient (D) None of these

Last Answer : (C) Joule-Thompson co-efficient

Description : The two specific heats of gases are related by : (1) Cp + Cv = RJ (2) Cp –Cv = R/J (3) Cp – Cv = RJ (4) Cp /Cv = R

Last Answer :  Cp –Cv = R/J

Description : The gas constant is equal to  a. Cp – Cv  b. Cp + Cv  c. Cp – Cv + k  d. None of the above

Last Answer : Cp – Cv

Description : Characteristic gas constant of a gas is equal to  (a) C/Cv  (b) Cv/Cp  (c) Cp – Cv  (d) Cp + Cv  (e) Cp x Cv

Last Answer : Answer : c

Description : If the molar heat capacities (Cp or Cv) of the reactants and products of a chemical reaction are identical, then, with the increase in temperature, the heat of reaction will (A) Increase (B) Decrease (C) Remain unaltered (D) Increase or decrease; depends on the particular reaction

Last Answer : (C) Remain unaltered

Description : In the equation, PVn = constant, if the value of n is in between 1 and y (i.e. Cp/Cv), then it represents a reversible __________ process. (A) Isometric (B) Polytropic (C) Isentropic (D) Isobaric

Last Answer : (B) Polytropic

Description : In the equation PVn = constant, if the value of n = y = Cp/Cv, then it represents a reversible __________ process. (A) Isothermal (B) Adiabatic (C) Isentropic (D) Polytropic

Last Answer : (C) Isentropic

Description : In case of compression of one kg of air, the work done will be the least, when the value of polytropic index 'n' is (A) 1 (B) 1.4 (C) 1.5 (D) Y = Cp/Cv

Last Answer : A) 1

Description : The value of y = cp/cv. at < 500°C for air & most common gases can be safely assumed to be (A) 0.8 (B) 1 (C) 1.4 (D) 1.8

Last Answer : Option C

Description : Calculate the recoverable waste heat (Q, in kCal/hour) from flue gases using the followingparameters: V (flow rate of the substance) 2000 m3/hr r (density of the flue gas): 0.9 kg/m3 Cp (specific heat ... (temperature difference): 120 oC h (recovery factor): 50% a. 21600 b. 43200 c. 25600 d. 34000

Last Answer : 21600

Description : For an ideal gas, Cp- Cvis (A) R (B) -R (C) 0 (D) (3/2) R

Last Answer : (A) R

Description : . The entropy change in a reversible isothermal process, when an ideal gas expands to four times its initial volume is (A) R loge 4 (B) R log10 4 (C) Cv log10 4 (D) Cv loge 4

Last Answer : (A) R loge 4

Description : . The entropy change in a reversible isothermal process, when an ideal gas expands to four times its initial volume is (A) R loge 4 (B) R log10 4 (C) Cv log10 4 (D) Cv loge 4

Last Answer : (A) R loge 4

Description : General gas equation is  (a) PV=nRT  (b) PV=mRT  (d) PV = C  (c) PV=KiRT  (e) Cp-Cv = Wj

Last Answer : Answer : b

Description : One kg of gas occupying 0.1m^3 at pressure of 14 bar is expanded at constant pressure to 0.2m^3. Determine an initial and final temperature of gas. Take Cp=1.008KJ/KgK, Cv =0.72KJ/KgK.

Last Answer : V1=0.1m^3 V2=0.2 m^3 P1=P2=14 bar Cp=1.008 KJ/KgK Cv=0.72 KJ/KgK R=Cp-Cv R=1.008-0.72 R=0.288KJ/KgK Characteristic gas equation,  P1V1=mRT1 14*10^5*0.1=1*288*T1 T1=486.11K For constant pressure process, V1/T1=V2/T2 0.1/486.11=0.2/T2 T2=972.22K

Description : Cp /Cv is termed as (A) Adiabatic constant (B) Mach number (C) Weber number (D) Prandtl number

Last Answer : (A) Adiabatic constan

Description : For a constant pressure reversible process, the enthalpy change (ΔH) of the system is (A) Cv.dT (B) Cp.dT (C) ∫ Cp.dT (D) ∫ Cv.dT

Last Answer : (C) ∫ Cp.dT

Description : PVγ = Constant (where, γ = Cp/Cv) is valid for a/an __________ process. (A) Isothermal (B) Isentropic (C) Isobaric (D) Adiabatic

Last Answer : (D) Adiabatic

Description : The value of Cp & Cv respectively for monatomic gases in Kcal/kg Mole.°K are (A) 5 & 3 (B) 3.987 & 1.987 (C) 1.987 & 0.66 (D) 0.66 & 1.987

Last Answer : A) 5 & 3

Description : Give relation between Cp and Cv.

Last Answer : Ans. Cp – Cv = R

Description : Heat transfer co-efficient (h) for a fluid flowing inside a clean pipe is given by h = 0.023 (K/D) (DVρ/µ) 0.8 (CP .µ/k) 0.4 . This is valid for the value of NRe equal to (A) < 2100 (B) 2100-4000 (C) > 4000 (D) > 10000

Last Answer : (D) > 10000

Description : Pick out the wrong statement. (A) Cp of monatomic gases such as metallic vapor is about 5 kcal/kg.atom (B) The heat capacity of solid inorganic substance is exactly equal to the ... isolated system (D) At absolute zero temperature, the heat capacity for many pure crystalline substances is zero

Last Answer : (C) There is an increase in entropy, when a spontaneous change occurs in an isolated system

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 : A certain gas, with cp = 0.529Btu/ lb. °Rand R = 96.2ft.lb/lb. °R, expands from 5 cu ft and 80°F to 15 cu ft while the pressure remains constant at 15.5psia. Compute for T2.  a.1520°R  b. 1620°R  c. 1720°R  d. 1820°R formula: T2= T1V2/V1

Last Answer : 1620°R

Description : 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 kf\g of this gas at constant pressure when the initial temp is 32.2°C? 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)

Last Answer : 339.4 K

Description : A certain gas with cp = 0.529Btu/lb°R and R = 96.2ft/lbºR expands from 5 ft and 80ºF to 15 ft while the pressure remains constant at 15.5 psia.  a. T2=1.620ºR, ∫H = 122.83 Btu  b. T2 = 2°R, ∫H = 122.83 Btu  c. ... , ∫H = 122.83 Btu  d. T2 = 1°R, ∫H = 122.83 Btu T2= V2(t2)/V1 and ∫H = mcp (T2-T1)

Last Answer : T2=1.620ºR, ∫H = 122.83 Btu

Description : A certain gas, with cp = 0.529Btu/lb.°R and R = 96.2 ft.lb/lb.°R, expands from 5 cu ft and 80°F to 15 cu ft while the pressure remains constant at 15.5 psia. Compute for T2. (Formula: T2= T1V2/V1)  a. 460°R  b. 270°R  c. 1620 °R  d. None of the above

Last Answer : 1620 °R

Description : For a certain gas R = 320 J/kg.K and cv= 0.84kJ/kg.K. Find k?  a. 1.36  b. 1.37  c. 1.38  d. 1.39 formula: k= R / cv+1

Last Answer : 1.38

Description : 1m3 of an ideal gas at 500 K and 1000 kPa expands reversibly to 5 times its initial volume in an insulated container. If the specific heat capacity (at constant pressure) of the gas is 21 J/mole . K, the final temperature will be (A) 35 K (B) 174 K (C) 274 K (D) 154 K

Last Answer : (C) 274 K

Description : To obtain integrated form of Clausius-Clapeyron equation, ln (P2/P1) = (∆HV/R) (1/T1- 1/T2) from the exact Clapeyron equation, it is assumed that the (A) Volume of the liquid phase is negligible compared to ... gas (C) Heat of vaporisation is independent of temperature (D) All (A), (B) & (C)

Last Answer : (D) All (A), (B) & (C)

Description : Specific volume of an ideal gas is (A) Equal to its density (B) The reciprocal of its density (C) Proportional to pressure (D) None of these

Last Answer : (B) The reciprocal of its density

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 : 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 : Adiabatic bulk modulus is equal to:  A. Υ × P; where Υ: the ratio of the specific heat capacities of the gas, P: pressure B. Pressure C. The ratio of the specific heat capacities of the gas D. Υ ⁄ P; where Υ: the ratio of the specific heat capacities of the gas, P: pressure

Last Answer : Υ × P; where Υ: the ratio of the specific heat capacities of the gas, P: pressur

Description : Isothermal bulk modulus is equal to A. Υ × P; where Υ: the ratio of the specific heat capacities of the gas, P: pressure B. Pressure C. The ratio of the specific heat capacities of the gas D. Υ ⁄ P; where Υ: the ratio of the specific heat capacities of the gas, P: pressure

Last Answer : Pressure

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 : Thermal diffusivity of a material (A) Has the unit m2 /sec (B) Is defined as K/ρ . Cp (C) Is the ratio of thermal conductivity to thermal capacity (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)