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GATE Chemical Engineering
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GATE Chemical Engineering
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A n automobile plant contracted to buy shock absorbers from two suppliers X and Y. X supplies 60% and Y supplies 40% of the shockabsorbers.
All shock absorbers are subjected to a qualitytest.
The ones that pass the quality test are consideredreliable.
Of X’s shock absorbers, 96% are reliable Of Y’s shock absorbers, 72% arereliable.
The probability that a randomly chosen shock absorber, which is found to be reliable, is made by Y 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 an increase in T and P
K increases with T and decreases with P
K decreases with an increase in T and is independent of P
K is independent of T and P
A first order liquid phase reaction is carried out isothermally at a steady state in a CSTR and 90% conversion isattained.
With the same inlet conditions and for the same overall conversion, if the CSTR is replaced by two smaller and identical isothermal CSTRs in series, the % reduction in total volume, to the nearest integer, is ____________
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 rate of absorption of the solute from the gas stream
have the same rate of absorption of the solute from the gas stream
have a higher rate of absorption of the solute from the gas stream
have a lower height of transfer unit
In a counter-flow double pipe heat exchanger, oil (m = 2 kg/s, CP = 2.1 kJ/kg.°C) is cooled from 90 °C to 40 °C by water (m = 1 kg/s, CP 4.2 kJ/kg.°C) which enters the inner tube at 10 °C. The radius of the inner tube is 3 cm and its length is 5 m. Neglecting the wall resistance, the overall heat transfer coefficient based on the inner radius, in kW / m2. K, is
For heat transfer across a solid-fluid interface, which one of the following statements is NOT true when the Biot number is very small compared to 1
Temperature profile within the solid is nearly uniform
Conduction resistance in the solid is very small compared to convection resistance in the fluid
Temperature drop in the fluid is significant
Temperature drop in the solid is significant
Water is flowing under laminar conditions in a pipe of length L
. If the diameter of the pipe is doubled, for a constant volumetric flow rate, the pressure drop across the pipe
decreases 2 times
increases 16 times
decreases 16 times
increases 2 times
In the elutriation leg of a commercial crystallizer containing a mixture of coarse and very fine crystals of the same material, a liquid is pumped verticallyupward.
The liquid velocity is adjusted such that it is slightly lower than the terminal velocity of the coarse crystalsonly.
the very fine and coarse crystals will both be carried upward by the liquid
the coarse crystals will be carried upward and the very fine crystals will settle
the very fine crystals will be carried upward and the coarse crystals will settle
the very fine and coarse crystals will both settle at the bottom of the tube
An open tank contains two immiscible liquids of densities
(800 kg/m3 and 1000 kg/m3) as shown in thefigure.
If g = 10 m/s2, under static conditions, the gauge pressure at the bottom of the tank in Pa is ___________
The first order liquid phase reaction A ---> P is conducted isothermally in a plug flow reactor of 5 litervolume.
The inlet volumetric flow rate is 1 liter/min and the inlet concentration of A is 2 mole/liter.
The plug flow reactor is replaced by 3 mixed flow reactors in series, each of 2.0 litersvolume.
The exact conversion of A (in %) is
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
Calculate the heat required (in kJ, up to 1 digit after the decimal point) to raise the temperature of 1 mole of a solid material from 100oC to1000oC.
The specific heat
(CP) of the material (in J/mol-K) is expressed as CP = 20 + 0.005T, where T is in K. Assume no phasechange.
11 to 12
21 to 22
32 to 33
38 to 39
An isothermal liquid phase zero order reaction A --> B (k = 0.5 mol/m3 -s) is carried out in a batchreactor.
The initial concentration of A is 2 mol/m3. At 3 seconds from the start of the reaction, the concentration of A in mol/m3 is __________
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
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-3, Q-2, R-4, S-1
P-2, Q-4, R-3, S-1
P-3, Q-4, R-2, S-1
Group 1 Group 2(P) Viscosity
(1) Pyrometer(Q) Pressure
(2) Hot wire anemometer(R) Velocity
(3) Rheometer(S) Temperature
(4) Piezoelectric element
P-3, Q-4, R-2, S-1
P-3, Q-4, R-1, S-2
P-4, Q-3, R-2, S-1
P-4, Q-3, R-1, S-2
Which one of the following options is the closest in meaning to the word given below? Mitigate
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
7.3 to 7.5
4.7 to 4.9
5.6 to 5.8
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 _________
Taking the acceleration due to gravity to be 10 m/s2, the separation factor of a cyclone 0.5 m in diameter and having a tangential velocity of 20 m/s near the wall is _________
In the manufacture of sulphuric acid by the contact process, the catalytic oxidation of SO2 is carried out in multiple stages mainly to
increase the reaction rate by providing inter-stage heating
increase the overall conversion by providing inter-stage heating
increase the overall conversion by providing inter-stage cooling
decrease the overall conversion by removing sulphur trioxide between stages
Evaluate ( Note: C is a constant ofintegration.
ex/(ex - 1) + C
ln[ex/(ex - 1)] + C
ln(1 - e-x) + C
ln (ex - 1)/ex + C
All engineering students should learn mechanics, mathematics and how to docomputation.
I II III IV Which of the above underlined parts of the sentence is not appropriate
If the temperature of saturated water is increased infinitesimally at constant entropy, the resulting state of water will be
Liquid – vapor coexistence
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
A control valve, with a turndown ratio of 50, follows equal percentagecharacteristics.
The flow rate of a liquid through the valve at 40% stem position is 1 m3/h. What will be the flow rate in m3/h at 50% stem position, if the pressure drop across the valve remains unchanged? (Up to 2 digits after the decimalpoint.
Given the sequence of terms, AD CG FK JP, the next term is
A thermometer initially at 100°C is dipped at t = 0 into an oil bath, maintained at 150°C. If the recorded temperature is 130°C after 1 minute, then the time constant of thermometer (in min) is
A Newtonian fluid of viscosity μ flows between two parallel plates due to the motion of the bottom plate
(as shown below), which is moved with a velocity V
. The top plate isstationary.
The steady, laminar velocity profile in the x - direction is
V[1 - (y/b)2]
V[(y/b)2 - 1]
V[1 - y/b]
A batch reactor produces 1 * 105 kg of a product peryear.
The total batch time (in hours) of the reactor is k√PB, where PB is the product per batch in kg and k = 1.0 h/√kg The operating cost of the reactor is Rs. 200/h. The total annual fixed charges are Rs. 340 * PB and the annual raw material cost is Rs. 2 * 106 The optimum size (in kg) of each batch
(adjusted to the nearest integer) is