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 : 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 : 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.
Last Answer : Answer : b
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 : Absolute zero pressure will occur (a) at sea level (b) at the center of the earth (c) when molecular momentum of the system becomes zero (d) under vacuum conditions (e) at a temperature of – 273 °K
Last Answer : Answer : c
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 : 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 : 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 : The surface tension of a liquid, at critical temperature is (A) Indeterminate (B) Zero (C) Infinity (D) Same as that at any other temperature
Last Answer : Option B
Description : The condition of perfect vacuum, i.e., absolute zero pressure can be attained at (a) a temperature of – 273.16°C (b) a temperature of 0°C (c) a temperature of 273 °K (d) a negative pressure and 0°C temperature (e) can’t be attained.
Last Answer : Answer : a
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 reaction A → B is conducted in an adiabatic plug flow reactor (PFR). Pure A at a concentration of 2 kmol/m3 is fed to the reactor at the rate of 0.01 m3 /s and at a temperature of 500 K. If the exit ... /kmole. K (may be assumed to be independent of temperature)) (A) 400 (B) 500 (C) 600 (D) 1000
Last Answer : (C) 600
Description : The critical pressure at which the latent heat of vaporisation of steam becomes zero is __________ Kg/cm2. (A) 273.15 (B) 225.65 (C) 100.03 (D) 373.15
Last Answer : (B) 225.65
Description : In a heat exchanger, one transfer unit means (A) A section of the exchanger in which change in temperature of one stream equals the average driving force in the section (B) The size of the exchanger in which heat transfer rate is 1 kcal/hr (C) Both (A) and (B) (D) None of these
Last Answer : (A) A section of the exchanger in which change in temperature of one stream equals the average driving force in the section
Description : Gibbs free energy of a pure fluid approaches __________ as the pressure tends to zero at constant temperature. (A) Infinity (B) Minus infinity (C) Zero (D) None of these
Last Answer : (B) Minus infinity
Description : At constant temperature and pressure, for one mole of a pure substance, the ratio of the free energy to the chemical potential is (A) Zero (B) One (C) Infinity (D) Negative
Last Answer : (B) One
Description : No liquid can exist as liquid at (a) – 273 °K (b) vacuum (c) zero pressure (d) centre of earth (e) in space.
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 : 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 : 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.
Description : What is the value of the universal gas constant in kJ/kmol K? ∙ A. 10.73 B. 1.986 C. 8.314 D. 1545
Last Answer : 8.314
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 : 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 : The heat flux (from outside to inside) across an insulating wall with thermal conductivity, K = 0.04 W/m.°K and thickness 0.16m is 10 W/m2 . The temperature of the inside wall is - 5°C. The outside wall temperature is (A) 25°C (B) 30°C (C) 35°C (D) 40°C
Last Answer : (C) 35°C
Description : A furnace is made of a refractory brick wall of thickness 0.5 metre and thermal conductivity 0.7 W/m.°K For the same temperature drop and heat loss, this refractory wall can be replaced by a layer of diatomaceous earth of ... and thickness __________ metre. (A) 0.01 (B) 0.1 (C) 0.25 (D) 0.5
Last Answer : (B) 0.1
Description : Bharani sells a novel at a gain of 40%. if he had bought it at 20% less and sold it for Rs. 70 more which equals to 350% of CP. The CP of the novel is
Last Answer : Let CP= x SP= 140x/100 = 14x/10 CP= 80% 0f x= 8x/10 then, SP =14x/10+70 14x/10 + 70= 350%of 8x/10 14x/10+70=350/100*8x/10=28x/10 70=28x/10-14x/10 70=14x/10 X=700/14 X=50
Description : Pressure-enthalpy chart is useful in refrigeration. The change in internal energy of an ideal fluid used in ideal refrigeration cycle is (A) Positive (B) Negative (C) Zero (D) Infinity
Last Answer : C) Zero
Description : Specific heat of a gas for a reversible adiabatic process is (A) Negative (B) Zero (C) Infinity (D) None of these
Last Answer : (B) Zero
Description : In a parallel flow heat exchanger, if the outlet temperature of hot and cold fluids are the same, then the log mean temperature difference (LMTD) is (A) Minimum (B) Maximum (C) Zero (D) Infinity
Last Answer : (C) Zero
Description : As the temperature is lowered towards the absolute zero, the value of ∂(∆F)/∂T, then approaches (A) Unity (B) Zero (C) That of the heat of reaction (D) Infinity
Last Answer : B) Zero
Description : Thermal efficiency of a Carnot engine can approach 100%, only when the temperature of the (A) Cold reservoir approaches zero (B) Hot reservoir approaches infinity (C) Either (A) or (B) (D) Neither (A) nor (B)
Last Answer : C) Either (A) or (B)
Description : As the temperature is lowered towards the absolute zero, the value of the quantity (∂∆F/∂T) approaches (A) Zero (B) Unity (C) Infinity (D) None of these
Last Answer : (A) Zero
Description : The unity of Planck's constant 'h' in the equation, E = hv is (A) J/s (B) J.S (C) J/kmol (D) kmol/J
Last Answer : (B) J.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 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 : Critical pressure of a liquid is the pressure (a) above which liquid will remain liquid (b) above which liquid becomes gas (c) above which liquid becomes vapour (d) above which liquid becomes solid
Last Answer : Ans: a
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 : With increase in pressure (above atmospheric pressure), the Cp of a gas (A) Increases (B) Decreases (C) Remains unchanged (D) First decreases and then increases
Last Answer : (A) Increases
Description : The expression for entropy change, ΔS = n Cp. ln (T2/T1), is valid for the __________ of a substance. (A) Simultaneous pressure & temperature change (B) Heating (C) Cooling (D) Both (B) and (C)
Last Answer : (D) Both (B) and (C)
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 : 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 : Pick out the wrong statement. (A) Superheated steam is preferably not used for process heating because of its low heat transfer film co-efficient (B) In a shell and tube heat exchanger ... surface heat exchangers, when the direction of fluid flow is parallel to the axis of the tube
Last Answer : (C) S.I. unit of fouling factor is Watt/m2 .°K
Description : The speed at which the shaft runs so that the additional deflection of the shaft from the axis of rotation becomes ___________, is known as critical or whirling speed. (A) zero (B) minimum (C) maximum (D) infinite
Last Answer : (D) infinite
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 : The variation of thermal conductivity of a metal with temperature is often correlated using an expression of the form K = K0 + at, where, K is the thermal conductivity and T is the temperature (in °K). The units of 'a' in SI system will be (A) W/m.k (B) W/m (C) W/m.k
Last Answer : (C) W/m.k
Description : A composite flat wall of a furnace is made of two materials 'A' and 'B'. The thermal conductivity of 'A' is twice of that of material 'B', while the thickness of layer of 'A' is half that of B. If the temperature ... drop (in °K) across the layer of material 'A' is (A) 125 (B) 133 (C) 150 (D) 160
Last Answer : (D) 160
Description : Optimum preheating temperature for pitch creosote mixture (PCM) which is also termed as C.T.F-200, before atomisation through burners is (A) 200 °F (B) 200 °C (C) 200 °K (D) 200 °R
Last Answer : (A) 200 °F