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GATE Chemical Engineering
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GATE Chemical Engineering
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The block diagram of a system with a proportional controller is shown belowA unit step input is introduced in the setpoint.
The value of Kc to provide a critically damped response for U = 0, Tp = 8 and Tm = 1 is
Consider the following set of linear algebraic equations x1 + 2x2 + 3x3 = 2 x2 + x3 = - 1 2x2 + 2x3 = 0The system has
a unique solution
an infinite number of solutions
only the trivial solution
The packing of an existing absorption tower is replaced with a new type ofpacking.
The height of the packing and the inlet conditions are maintained the same asbefore.
Tests reveal that the number of transfer units is lower thanbefore.
This indicates that the tower with the new packing, when compared to that with the old packing, will
have a lower height of transfer unit
have a higher rate of absorption of the solute from the gas stream
have a lower rate of absorption of the solute from the gas stream
have the same rate of absorption of the solute from the gas stream
In petroleum refining, catalytic reforming is used to convert
Gas oil to diesel and gasoline
Light olefins to gasoline
Paraffins to hydrogen and carbon monoxide
Paraffins and naphthenes to aromatics
In a double pipe counter-current heat exchanger, the temperature profiles shown in the figure wereobserved.
During operation, due to fouling inside the pipe, the heat transfer rate reduces to half of the originalvalue.
Assuming that the flow rates and the physical properties of the fluids do not change, the LMTD (in °C) in the new situation is
A thermocouple having a linear relationship between 0oC and 350oC shows an emf of zero and 30.5 mV, respectively at these twotemperatures.
If the cold junction temperature is shifted from 0oC to 30oC, then the emf correction (in mV) is
The one - dimensional unsteady state heat conduction equation in a hollow cylinder with a constant heat source q is If A and B are arbitrary constants, then the steady state solution to the above equation is
T(r) = - qr2/2 + A/r + B
T(r) = qr2/4 + A ln r + B
T(r) = - qr2/4 + A ln r + B
T(r) = A ln r + B
Given the sequence of terms, AD CG FK JP, the next term is
The half-life of an nth order reaction in a batch reactor depends on
the rate constant, initial reactant concentration, and the order of the reaction
only the rate constant and the initial reactant concentration
only the rate constant and the order of the reaction
only the rate constant
For a Newtonian fluid flowing in a circular pipe under steady state conditions in fully developed laminar flow, the Fanning friction factor is
0.0014 + 0.125/Re0.32
A political party orders an arch for the entrance to the ground in which the annual convention is beingheld.
The profile of the arch follows the equation y = 2x - 0.1x2 where y is the height of the arch inmeters.
The maximum possible height of the arch is
In the McCabe-Thiele diagram, if the x -coordinate of the point of intersection of the q -line and the vapor-liquid equilibrium curve is greater than the x -coordinate of the feed point, then the quality of the feed is
liquid below bubble point
If the temperature of saturated water is increased infinitesimally at constant entropy, the resulting state of water will be
Liquid – vapor coexistence
The reaction A(liq) + B(gas) ---> C(liq) + D(gas), is carried out in a reactor followed by a separator as shown below Notation: Molar flow rate of fresh B is FFB Molar flow rate of A is FA Molar flow rate of recycle gas is FRG Mole fraction of B in recycle gas is YRB Molar flow rate of purge gas is FPG Molar flow rate of C is FC Here, FFB = 2 mol/s; FA = 1 mol/s, FB/FA = 5 and A is completelyconverted.
I f the ratio of recycle gas to purge gas (FRG/FPG) is 4 then YRB is
Group 1 Group 2(P) Viscosity
(1) Pyrometer(Q) Pressure
(2) Hot wire anemometer(R) Velocity
(3) Rheometer(S) Temperature
(4) Piezoelectric element
P-4, Q-3, R-2, S-1
P-4, Q-3, R-1, S-2
P-3, Q-4, R-2, S-1
P-3, Q-4, R-1, S-2
The reaction A(liq) + B(gas) ---> C(liq) + D(gas), is carried out in a reactor followed by a separator as shown below Notation: Molar flow rate of fresh B is FFB Molar flow rate of A is FA Molar flow rate of recycle gas is FRG Mole fraction of B in recycle gas is YRB Molar flow rate of purge gas is FPG Molar flow rate of C is FC Here, FFB = 2 mol/s; FA = 1 mol/s, FB/FA = 5 and A is completely converted If YRB = 0.3, the ratio of recycle gas to purge gas (FRG/FPG) is
The units of the isothermal compressibility are
A hole of area 1 cm2 is opened on the surface of a large spherical cavity whose inside temperature is maintained at 727 oC. The value of Stefan-Boltzmann constant is 5.67 * 10-8 W/m2 - K4. Assuming black body radiation, the rate at which the energy is emitted (in W) by the cavity through the hole, up to 3 digits after the decimal point, is ________
1.2 to 1.4
5.6 to 5.8
4.7 to 4.9
7.3 to 7.5
Consider the reaction scheme shown below Both the reactions are first-order.
The activation energies for k1 and k2 are 80 and 20 kJ/mol,respectively.
To maximize the yield of B, it is preferable to use
PFR and low temperature
CSTR and high temperature
CSTR and low temperature
PFR and high temperature
Match the reactant-product combination in Group 1 with the unit process in Group 2.Group 1 Group 2(P) propylene - butanol
(1) Pyrolysis(Q) cumene - phenol
(2) Dehydrogenation(R) butane - butadiene
(3) Hydroformylation(S) ethylene dichloride - vinyl chloride
P-1, Q-3, R-2, S-4
P-2, Q-4, R-3, S-1
P-3, Q-2, R-4, S-1
P-3, Q-4, R-2, S-1
The effectiveness of a heat exchanger in the &NTU method is defined as
A bed of spherical glass beads
(density 3000 kg/m3 diameter 1 mm, bed porosity 0.5) is to be fluidized by a liquid of density 1000 kg/m3 and viscosity 0.1 Pa.s. Assume that the Reynolds number based on particle diameter is very small compared toone.
If g = 10 m/s2 then the minimum velocity (in m/s) required to fluidize the bed is
3.33 * 10-1
3.33 * 10-4
A unit gain 2nd order underdamped process has a period of oscillation 1 second and decay ratio 0.25. The transfer function of the process is
1/(0.1176 s2 + 0.021 s + 1)
1/(0.067 s2 + 0.024 s + 1)
1/(0.024 s2 +0.067 s + 1)
1/(0.021 s2 + 0.1176 s + 1)
Consider the drying operation shown in the figure below for a solid loading
(dry basis) of 50 kg/m2 with a constant drying rate of 5 kg/m2.h. The falling rate of drying is linear with moisturecontent.
The drying time (in hrs) required to reduce an initial moisture content of 25% to a final moisture content of 2% is
A gaseous system contains H2, I2, and HI, which participate in the gas-phase reaction2 HI H2 + I2 At a state of reaction equilibrium, the number of thermodynamic degrees of freedom is _________
For an exothermic reversible reaction, which one of the following correctly describes the dependence of the equilibrium constant ( K ) with temperature (T ) and pressure ( P )
K increases with T and decreases with P
K is independent of T and P
K decreases with an increase in T and is independent of P
K increases with an increase in T and P
The gas phase decomposition of azomethane to give ethane and nitrogen takes place according to the following sequence of elementaryreactions.
Using the pseudo-steady-state-approximation for [
(CH3)2 N2], the order with respect to azomethane in the rate expression for the formation of ethane, in the limit of high concentrations of azomethane, is ___________
The number of emails received on six consecutive days is 11, 9, 18, 18, 4 and 15,respectively.
What are the median and the mode for these data
12.5 and 18, respectively
13 and 18, respectively
18 and 11, respectively
13 and 12.5, respectively
Liquid reactant A decomposes as follows A --> R rR = k1C2A k1 = 0.5 m3/mol-s A --> S rS = k2CA k2 = 1 s-1 An aqueous feed of composition CA0 = 30 mol/m3, CR0 = 2 mol/m3 and CS0 = 1 mol/m3 enters a CSTR in which the above reactionsoccur.
Assume isothermal and steady state conditions If the conversion of A is 80 %, the concentration of R in the exit stream in mol/m3, to the nearest integer, is _________
The vapor-liquid equilibrium curve of a binary mixture A-B, may be approximated by a linear equation over a narrow range of liquid mole fractions ( 0.2 < xA < 0.3) as follows y*A = 1.325 xA + 0.121 Here y*A is the mole fraction of A in thevapor.
100 moles of a feed (xA, F = 0.28) is batch distilled to a final residue (xA, W = 0.2). Using the Rayleigh equation, the number of moles of the residue left behind in the distillation unit, up to 2 digits after the decimal point, is ____________
45 to 46
55 to 56
66 to 67
85 to 86