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 : The value of gas constant 'R' is (A) 1.987 cal/gm mole °K (B) 1.987 BTU/lb. mole °R (C) Both (A) and (B) (D) Neither (A) nor (B)
Last Answer : (C) Both (A) and (B)
Description : Molar heat capacity of water in equilibrium with ice at constant pressure is __________ Kcal/kg mole. °K (A) 0 (B) ∞ (C) 50 (D) 100
Last Answer : (B) ∞
Description : Cp of a gas at its critical temperature and pressure (A) Becomes zero (B) Becomes infinity (C) Equals 1 kcal/kmol °K (D) Equals 0.24 kcal/kmol °K
Last Answer : (B) Becomes infinity
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 : 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 : 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 : 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 : 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 : 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 : If the specific heats of a gas and a vapor are 0.2KJ/Kg.°K and 1.5 KJ/Kg.°K respectively, and the humidity is 0.01; the humid heat in KJ/°Kg. is (A) 0.31 (B) 0.107 (C) 0.017 (D) 0.215
Last Answer : (D) 0.215
Description : Internal energy of an element at 1 atm and 25° C is __________ kcal/kg.mole. (A) 0 (B) 273 (C) 25 (D) None of these
Last Answer : (A) 0
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 : If heat contents of CH4, C2H4 and C3H8 are -17.9, 12.5 and -24.8 kcal/mole respectively, than ΔH for the reaction CH4(g) + C2H4(g) ⇌ C3H8(g) will be __________ Kcal. (A) -19.4 (B) -30.2 (C) 55.2 (D) -55.2
Last Answer : (A) -19.4
Description : For which pair of the fuel gases, calorific value (C.V.) of one fuel is almost double that of the other on volume basis (i.e., kcal/Nm3 ), while the C.V. is same on weight basis (i.e., kcal/kg)? (A) Propane and acetylene (B) Propane and LPG (C) Sewage gas and gobar gas (D) B.F. gas and coke oven gas
Last Answer : (A) Propane and acetylene
Description : For which pair of the fuel gases, calorific value (C.V.) of one fuel is almost double that of the other on volume basis (i.e., kcal/Nm3) while the C.V. is same on weight basis (i.e., kcal/kg)? (A ... and acetylene (B) Propane and LPG (C) Sewage gas and gobar gas (D) B.F gas and coke oven gas
Last Answer : D) B.F gas and coke oven gas
Description : In case of physical adsorption, the heat of adsorption is of the order of __________ kcal/kg.mole. (A) 100 (B) 1000 (C) 10000 (D) 100000
Last Answer : (B) 1000
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 : Overall heat transfer co-efficient for cooling of hydrocarbons by water is about (A) 50 -100 Kcal/hr.m2 .°C (B) 50 -100 W/m2 .°K (C) 50 -100 BTU/hr. ft. 2°F (D) 1000 - 1500 BTU/hr. ft. 2°F
Last Answer : (C) 50 -100 BTU/hr. ft. 2°F
Description : A BTU/hr.ft. 2 °F is equal to (A) 1 kcal/hr. m2°C (B) 4.88 kcal/hr. m. 2°C (C) 1 kcal/hr. m2 .°K (D) None of these
Last Answer : (B) 4.88 kcal/hr. m. 2°C
Description : Trouton's ratio is given by (where λb, = molal heat of vaporisation of a substance at its normal boiling point, kcal/kmol Tb = normal boiling point, °K) (A) λb/Tb (B) Tb/λb (C) √(λb/Tb) (D) √(Tb/λb)
Last Answer : (A) λb/Tb
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 : The relation among various mass transfer co-efficients (M.T.C) for ideal gases is given by (where, Kc & Km are M.T.C. for equimolar counter diffusion with concentration & mole fraction respectively as the driving ... (C) Kc = Kp . RT = Km . RT/p (D) None of these
Last Answer : (C) Kc = Kp . RT = Km . RT/p
Description : Cp /Cv is termed as (A) Adiabatic constant (B) Mach number (C) Weber number (D) Prandtl number
Last Answer : (A) Adiabatic constan
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 : 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 : 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 : 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)
Last Answer : D) All (A), (B) and (C)
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 : 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 : 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 : 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 : Melting point & boiling points of liquid oxygen are respectively - 218.8°C & - 183°C, while the same for liquid nitrogen is - 210°C & - 195.8°C respectively. The difference in melting points of liquid oxygen & liquid nitrogen is not equal to 8.8 (A) °C (B) °F (C) °K (D) °R
Last Answer : (B) °F
Description : Give relation between Cp and Cv.
Last Answer : Ans. Cp – Cv = R
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 : 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 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
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 : 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 : Experiments were conducted to determine the flux of a species A in a stagnant medium across a gas-liquid interface. The overall mass transfer coefficient based on the liquid side for dilute systems for the above was estimated to be 4 ... -4 (C) 5.6 10 -3 (D) 8.5 10 -3
Last Answer : (B) 8.5 × 10 -4
Description : What is the critical radius of insulation (cms) for a metallic cylinder, if the convective heat transfer co-efficient with the ambient atmosphere is 5 W/m2. °K? Thermal conductivity of metal and insulation material are 40 and 0.1 W/m.°K respectively. (A) 2 (B) 8 (C) 10 (D) 40
Last Answer : (A) 2
Description : The value of the product of molecular weight and the gas characteristic constant for all the gases in S.I. units is (a) 29.27 J/kmol°K (b) 83.14J/kmol°K (c) 848J/kmol°K (d) All J/kmol °K (e) 735 J/kmol °K.
Description : The noble gases have closed-shell electronic cordigaration and are monatomic gases under normal condition .The low bolling points of the ligher noble
Last Answer : The noble gases have closed-shell electronic cordigaration and are monatomic gases under normal condition .The low ... (C) pyramidal D. (D) T-shaped
Last Answer : The noble gases have closed-shell electronic cordigaration and are monatomic gases under normal condition .The ... B. planar C. pyramidal D. T-shaped
Last Answer : The noble gases have closed-shell electronic cordigaration and are monatomic gases under normal condition ... C. flammability D. high calorific value