)] of

a solid catalysed first order reaction is equal to (where, L = length of the

reactor, cm, D1 = diffusion co-efficient, cm2

/second).

(A) L √(K/D1

)

(B) 1/[L√(K/D1

)]

(C) 1

(D) ∞

**Description :** Which of the following is not a dimension-less group used in catalysis? (Where, D = dispersion co-efficient, cm2 /sec.D1 = diffusion co-efficient; cm2 /sec L = length of the reactor, cm t = time, sec, v = volumetric ... (D/vL) (B) Reduced time (vt/V) (C) Thiele modulus L √(k/D1 ) (D) None of these

**Last Answer :** (D) None of these

**Description :** What is the Thiele modulus of the solid catalysed first order reaction as shown in the bellow figure, if the pore diffusion offers negligible resistance to reaction? (A) < 5 (B) < 0.5 (C) > 1 (D) 5

**Last Answer :** (B) < 0.5

**Description :** Effectiveness factor (E) of a catalyst pellet is defined as, E = (actual rate within pore of the catalyst)/(rate if not snowed by pore diffusion), Effectiveness factor for a first order reaction is given by (where, T = Thiele modulus) (A) tan hT/T (B) tan T/T (C) tan hT/tan T (D) None of these

**Last Answer :** (A) tan hT/T

**Description :** For a first order chemical reaction in a porous catalyst, the Thiele modulus is 10. The effectiveness factor is approximately equal to (A) 0 (B) 1 (C) 0.1 (D) 0.5

**Last Answer :** (C) 0.1

**Description :** If Thiele modulus is __________, then the pore diffusion resistance in a catalyst may be considered as negligible. (A) 0 (B) ∞ (C) < 0.5 (D) > 0.5

**Last Answer :** (C) < 0.5

**Description :** Pick out the wrong statement. (A) In the McCabe-Thiele diagram for binary distillation, vertical feed line represents saturated liquid feed and horizontal feed line represents saturated vapour feed (B) In ... layers over a flat plate are of equal thickness, if Schmidt number is equal to unity

**Last Answer :** (C) For Laminar flow over a plate of length L, the local mass transfer coefficient at a distance L from the leading edge is 1.5 × 10 -2m/s. Then the average mass transfer co-efficient for the plate is 2 × 10 -2m/s

**Description :** A first order gaseous phase reaction is catalysed by a non-porous solid. The kinetic rate constant and the external mass transfer co-efficients are k and kg respectively. The effective rate constant (ke ff) is given by (A) ke ff = k + kg ( ... + kg )/2 (C) ke ff = (kkg ) 1/2 (D) 1/ke ff = 1/k + 1/kg

**Last Answer :** (D) 1/ke ff = 1/k + 1/kg

**Description :** The rough value of diffusion co-efficient of water vapor into air at 25°C may be about __________ cm2 /sec. (A) 0.25 (B) 2.5 (C) 1.25 (D) 0.0025

**Last Answer :** (A) 0.25

**Description :** 18.The total extension of a taper rod of length ‘L’ and end diameters ‘D1’ and ‘D2’, subjected to a load (P), is given of a. 4PL/ΠE. D1D2 b. 3PL/ΠE. D1D2 c. 2PL/ΠE. D1D2 d. PL/ΠE.D1D2 Where E=Young’s modulus of elasticity

**Last Answer :** a. 4PL/ΠE. D1D2

**Description :** For a solid catalysed chemical reaction, the effectiveness of solid catalyst depends upon the __________ adsorption. (A) Physical (B) Chemical (C) Both (A) and (B) (D) Neither (A) nor (B)

**Last Answer :** (B) Chemical

**Description :** Mass transfer co-efficient (K) and diffusivity (D) are related according to film theory as (A) K ∝ D (B) K ∝√D (C) K ∝ D1.5 (D) K ∝ D

**Last Answer :** (A) K ∝ D

**Description :** Mass transfer co-efficient 'K' according to penetration theory varies with mass diffusivity as (A) D0.5 (B) D (C) 1/D (D) D1.5

**Last Answer :** (A) D0.5

**Description :** If pore diffusion is the controlling step in a solid catalysed reaction, the catalyst (A) Porosity is very important (B) Porosity is of less importance (C) Internal surface area is utilised efficiently (D) None of these

**Last Answer :** (B) Porosity is of less importance

**Description :** A spherical porous catalyst particle of radius R is subjected to reactant A which reacts to form B by a zero order surface reaction A → B. Film mass transfer resistance is negligible and pore diffusion of A ... (D) Effectiveness factor for a zero order reaction cannot be 7/8 as it must always be 1

**Last Answer :** (A) Inner catalyst core of radius R/8 does not participate in reaction (

**Description :** For high conversion in a highly exothermic solid catalysed reaction, use a __________ bed reactor. (A) Fixed (B) Fluidised bed reactor followed by a fixed (C) Fixed bed reactor followed by a fluidised (D) Fluidised

**Last Answer :** (B) Fluidised bed reactor followed by a fixed

**Description :** Kinetics of a solid catalysed reaction can best be studied in a __________ reactor. (A) Batch (B) Plug-flow (C) Mixed (D) None of these

**Last Answer :** (C) Mixed

**Description :** Pick out the wrong statement. (A) The shear stress at the pipe (dia = D, length = L) wall in case of laminar flow of Newtonian fluids is (D/4L). ∆p (B) In the equation, T. gc = k. ... to motion (D) With increase in the Mach number >0.6, the drag co-efficient decreases in case of compressible fluids

**Last Answer :** (D) With increase in the Mach number >0.6, the drag co-efficient decreases in case of compressible fluids

**Description :** Pick out the wrong statement. (A) The binary diffusivity in liquids is of the order of 10 -5 cm2 /sec (B) Molecular diffusion in solid is much faster than that in liquids ( ... Poiseuille's law, the permeability decreases with increase in temperature for flow of a gas through a given capillary

**Last Answer :** (B) Molecular diffusion in solid is much faster than that in liquids

**Description :** The ratio of volume of mixed reactor to the volume of P.F.R. (for identical flow rate, feed composition and conversion) for zero order reaction is: (A) ∞ (B) 0 (C) 1 (D) > 1

**Last Answer :** (C) 1

**Description :** The Joule-Thomson co-efficient is defined as (∂T/∂P)H. Its value at the inversion point is (A) ∞ (B) 1 (C) 0 (D) -ve

**Last Answer :** (C) 0

**Description :** What is the value of Joule-Thomson co-efficient for an ideal gas? (A) +ve (B) -ve (C) 0 (D) ∞

**Last Answer :** (C) 0

**Description :** Joule-Thomson co-efficient which is defined as, η = (∂T/∂P)H = 1/Cp (∂H/∂T)P, changes sign at a temperature known as inversion temperature. The value of Joule-Thomson co-efficient at inversion temperature is (A) 0 (B) ∞ (C) +ve (D) -ve

**Last Answer :** (A) 0

**Description :** Effectiveness factor of a catalyst pellet is a measure of the __________ resistance. (A) Pore diffusion (B) Gas film (C) Chemical reaction (D) None of these

**Last Answer :** (A) Pore diffusion

**Description :** The Sieder-Tate correlation for heat transfer in turbulent flow in pipe gives Nu α Re 0.8 , where, Nu is the Nusselt number and Re is the Reynolds number for the flow. Assuming that this relation is valid, the heat transfer co-efficient ... pipe diameter (D) as (A) D-1.8 (B) D-0.2 (C) D0.2 (D) D1.8

**Last Answer :** (B) D-0.2

**Description :** Diffusion co-efficient of a metal in a solid solution depends upon its (A) Composition (B) Temperature (C) Both (A) & (B) (D) Neither (A) nor (B)

**Last Answer :** (C) Both (A) & (B)

**Description :** As per Taggart's formula, the capacity (kg/hr) of Jaw & Gyratory crushers (for gapes of 10 to 60 cms) is equal to (where, L = Length of feed opening, cms S = Maximum width of discharge opening, cms). (A) LS (B) 93 LS (C) 250 LS (D) √(LS)

**Last Answer :** (B) 93 LS

**Description :** In solid catalysed reactions the diffusional effects are more likely to affect the overall rate of reaction for (A) Fast reactions in catalyst of small pore diameter (B) Fast reaction in catalyst ... reactions in catalyst of small pore diameter (D) Slow reactions in catalyst of large pore diameter

**Last Answer :** (C) Slow reactions in catalyst of small pore diameter

**Description :** Primary purpose of a __________ nuclear reactor is to supply a high neutron flux of the order of 10 13 to 10 14neutrons/cm2 second. (A) Research (B) Power (C) Breeder (D) Homogeneous

**Last Answer :** (A) Research

**Description :** Steel rods are normally used for concrete reinforcement because concrete and steel have almost equal (A) Tensile strength (B) Compressive strength (C) Young's modulus (D) Thermal co-efficient of expansion

**Last Answer :** (D) Thermal co-efficient of expansion

**Description :** Which of the following unit operations makes use of Thiele-Geddes equation? (A) Liquid-liquid extraction (B) Solid-liquid extraction (C) Multi-component absorption with chemical reaction (D) Multi-component distillation

**Last Answer :** (D) Multi-component distillation

**Description :** Compressibility co-efficient for an absolutely compressible cake is (A) 0 (B) 1 (C) 0 to 1 (D) ∞

**Last Answer :** (B) 1

**Description :** Joule-Thomson Co-efficient at any point on the inversion curve is (A) ∞ (B) +ve (C) 0 (D) -ve

**Last Answer :** (C) 0

**Description :** Pick out the wrong statement. (A) In a first order reaction, A → products; the reaction becomes slower as it proceeds, because the concentration of A decreases and the rate is proportional to the concentration ... irreversible reaction, A + B → 2C is k.CA .CB , then the reaction is always elementary

**Last Answer :** (C) According to the penetration theory, the mass transfer co-efficient decreases, if the exposure time of an eddy to the solute decreases

**Description :** The value of NA/(NA + NB), for steady state equimolal counter diffusion of two gases 'A' and 'B' is (A) 1 (B) ∞ (C) 0.5

**Last Answer :** (B) ∞

**Description :** The value of NA/(NA + NB) for steady state molecular diffusion of gas 'A' through non-diffusing gas 'B' is (A) 1 (B) ∞ (C) 0.5 (D) 2

**Last Answer :** (A) 1

**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 :** Walls of a cubical oven are of thickness l, and they are made of material of thermal conductivity k. The temperature inside the oven is 100°C and the inside heat transfer co-efficient is 3k/l'. If the wall temperature ... wall temperature in degree centigrade? (A) 35.5 (B) 43.75 (C) 81.25 (D) 48.25

**Last Answer :** (C) 81.25

**Description :** For an ideal plug flow reactor, the value of Peclet number is (A) 0 (B) 1 (C) 10 (D) ∞

**Last Answer :** (A) 0

**Description :** A compound pipe of diameter d1, d2 and d3 having lengths l1, l2 and l3 is to be replaced by an equivalent pipe of uniform diameter d and of the same length (l) as that of the compound pipe. The size of the equivalent pipe is given by (A) l/d² = + + (B) l/d³ = + ) + (C) = + + (D)

**Last Answer :** Answer: Option D

**Description :** A standard steel tape of length 30 m and cross-section 15 1.0 mm was standardised at 25°C and at 30 kg pull. While measuring a base line at the same temperature, the pull applied was 40 kg. If the modulus of elasticity of ... (A) - 0.000909 m (B) + 0.0909 m (C) 0.000909 m (D) None of these

**Last Answer :** (A) - 0.000909 m

**Description :** Approximate value of the modulus of elasticity for steel is about __________ × 10 6kg/cm2 . (A) 0.5 (B) 2 (C) 40 (D) 75

**Last Answer :** (B) 2

**Description :** For an incompressible fluid, the bulk modulus of elasticity is (A) 5 kg/m3 (B) ∞ N/m2 (C) 1 N (D) 0 N/m

**Last Answer :** (B) ∞ N/m2

**Description :** In a rhombus if d1 = 16 cm, d2 = 12 cm, then the length of the side of the rhombus is (a) 8 cm (b) 9 cm (c) 10 cm (d) 12 cm

**Last Answer :** (c) 10 cm

**Description :** Speed ‘v’ with which wave travels through a medium is given by A. modulus of elasticity/density of the medium B. modulus of elasticity/√(density of the medium) C. √(modulus of elasticity/density of the medium) D. v=d/t

**Last Answer :** √(modulus of elasticity/density of the medium)

**Description :** Colebrook equation for friction factor in turbulent flow is given by, f -0.5 = -4 loge [(ε/D) + (1.26/NRe √F). It reduces to Nikuradse equation for a value of (ϵ/D) equal to (A) 0 (B) 1 (C) ∞ (D) 0.5

**Last Answer :** (B) 1

**Description :** The root mean square speed of molecules of a gas is equal to (where, m = mass of the molecule K = Boltzmann’s constant, T = absolute temperature) (A) √(2KT/m) (B) √(3KT/m) (C) √(6KT/m) (D) 3KT/m

**Last Answer :** (B) √(3KT/m)

**Description :** . In centrifugal pendulum absorber , the natural frequency in cycle per second can be given by A Fn =N √(R/L) B Fn =1/N √(R/L) C Fn =N/2 √(R/L) D Fn =N2 √(R/L)

**Last Answer :** A Fn =N √(R/L)

**Description :** In centrifugal pendulum absorber , the natural frequency in cycle per second can be given by A) Fn =N √(R/L) B) Fn =1/N √(R/L) C) Fn =N/2 √(R/L) D) Fn =N2 √(R/L)

**Last Answer :** A) Fn =N √(R/L)

**Description :** What is a conical pendulum? Show that its time period is given by 2π √(l cos θ)/g, where l is the length of the string,

**Last Answer :** What is a conical pendulum? Show that its time period is given by 2π\(\sqrt{\frac{l\,cos\, ... the vertical and g is the acceleration due to gravity.

**Description :** For a first order isothermal chemical reaction in a porous catalyst, the effectiveness factor is 0.3. The effectiveness factor will increase if the (A) Catalyst size is reduced or the ... the catalyst diffusivity is reduced (D) Catalyst size is increased or the catalyst diffusivity is increased

**Last Answer :** (B) Catalyst size is reduced or the catalyst diffusivity is increased