| Post Name | Lecturer in Chemical Engineering -Technical Education |
|---|---|
| Question Paper Code | 081/2024/OL |
| Category Code | 237/2023 |
| Date of Test | 4 July 2024 |
| Exam Type | Online Examination |
| Total Questions | 100 |
1
When does pressure intensity of the ļ¬uid would be same in all the directions?
Answer
C. When there is no relative motion of adjacent layers
2
How does pressure and power requirements relate to the gas density of a gas fan at a constant velocity and capacity?
Answer
A. Directly
3
How slugging in a ļ¬uidized bed can be avoided?
Answer
D. Shallow beds of solids and proper choice of particle size
4
What is the suitable example for variable oriļ¬ce ļ¬owmeter?
Answer
B. Rotameter
5
What is the drag coeļ¬cient of a bacterium (assume the size of 1 um) moving in water at the speed of 1 mm/s? (Assume the kinematic viscosity is /s)
Answer
C. 24000
6
Which of the following factors inļ¬uence the decrease in the pressure of a ļ¬uid when ļ¬ows under isothermal turbulent condition?
Answer
C. Both 1 and 2
7
Two parallel plates shear a Bingham ļ¬uid, with the bottom plate moving at 0.5 m/s and the top plate at 1.5 m/s in the same direction. The plate gap is 1 mm. Let the yield stress be 10 Kpa. What is the shear stress on the plates? Assume the dynamic viscosity as 10 Pas.
Answer
B. 20 KPa
8
A pipe (2 inches in diameter) requires a valve to be inserted. Suggest suitable valve
Answer
Question Cancelled
9
How the eļ¬ciency of the sedimentation tank (constant discharge rate) can be increased?
Answer
C. Increase in surface area
10
Centrifugal pumps are not recommended for which of the following ļ¬uids?
Answer
C. Thick molten soap at 80Ā°C
11
A screening operation is used to separate a particulate mixture into undersize and oversize fractions. If the feed contains 20% undersize particles by mass and the screen eļ¬ectiveness for the undersize fraction is 80%, what is the percentage of undersize in the undersize product?
Answer
A. 16
12
Which of the following combinations of ļ¬lter cake properties can provide the maximum ļ¬ltration rate in an industrial ļ¬ltration process?
Answer
C. High porosity but low compressibility
13
A spherical particle is settling freely in a ļ¬uid under gravity. Keeping all other parameters constant, which of the following will most signiļ¬cantly increase the terminal settling velocity of the particle?
Answer
B. Doubling the particle diameter
14
If the energy required to reduce the particle size of a feed whose 80% pass through a mesh of diameter 25 mm to a product whose 80% pass through a mesh of diameter 4 mm based on Bond's law is 20 kWh/ton, which of the following closely estimates the energy required to further reduce the particle size such that 80% pass through a mesh of diameter 1 mm?
Answer
D. 33 kWh/ton
15
Which of the following is a close estimate of the settling velocity in mm/s of a 50Ī¼ spherical particle of density 3700 kg/ settling in water at 20Ā°C?
Answer
C. 3.7
16
Which of the following is true for a particle reaching terminal velocity?
Answer
B. The particle has zero acceleration
17
Which of the following inļ¬uences the extent of separation in an industrial sorting classiļ¬er?
Answer
D. All of the above
18
For a pile of granular solids, the angle of repose is lower than the angle of internal friction when
Answer
B. Grains at the surface are more loosely bound than those inside the pile
19
The collection eļ¬ciency of a cyclone separator
Answer
A. Increases with particle diameter and particle density, but decreases with gas viscosity
20
The drag coefficient for a particle of diameter 4 mm and density 2500 kg/mĀ³ settling at 1.5 m/s in a stagnant fluid of density 1000 kg/mĀ³ and viscosity 0.01 PaĀ·s is
Answer
C. 0.44
21
Trouton's ratio is deļ¬ned as the fraction of
Answer
B. Heat of vaporization to the normal boiling point
22
Carbon black is produced by decomposition of methane as follows : The single pass conversion of methane is 60%. If the fresh feed is pure methane and 25% of the methane exiting the reactor is recycled, then calculate the molar ratio of fresh feed stream to recycle stream
Answer
B. 9
23
Find the normality of 98 grams/liter
Answer
B. 2
24
An evaporator is used to concentrate a liquor from 10 to 50 percent solids by weight. If the feed rate of the weak liquor is 1000 kg/h, determine the water evaporated in kg/h.
Answer
D. 800
25
Carbon monoxide combines with chlorine in the presence of a suitable catalyst to form phosgene according to the following reaction : After reaction, the products contained 12 moles of phosgene, 4 moles of chlorine and 10 moles of carbon monoxide. Assuming that the original mixture is free of phosgene, calculate the percentage conversion of the limiting reactant
Answer
C. 75.0
26
The ultimate analysis of coal gives
Answer
A. carbon, hydrogen, sulphur, nitrogen
27
Recycle streams will have purging operation for
Answer
B. reducing the accumulation of inerts
28
The heat of combustion of methane, carbon and hydrogen are , and kJ/mol respectively. Find the heat of formation of methane?
Answer
A. -75 kJ
29
The ratio of actual partial pressure exerted by the vapour to its vapour pressure at the same temperature, expressed as a percentage is called
Answer
D. percent relative saturation
30
The scale that is used to indicate the strength of sugar solution is
Answer
D. Brix
31
Which of the following statement is/are true? i. Heat interaction is a path function ii. Enthalpy change associated with a chemical reaction can be measured with a ļ¬ow calorimeter iii. Throttling process is an isenthalpic process
Answer
D. i, ii and iii
32
Ratio of fugacity to pressure is known as
Answer
A. fugacity coeļ¬cient
33
Determine the minimum amount of power required to maintain the temperature of a solution at 200K, when 100 kJ of heat per second is continuously removed from it. Consider the temperature of its surrounding as 300 K
Answer
B. 50 kW
34
All spontaneous processes are
Answer
B. irreversible
35
The following are the relations between activity coefficient (Ī³įµ¢) and mole fraction (xįµ¢) of a binary mixture at constant temperature and pressure. Pick the thermodynamically consistent relations
Answer
B. ln Ī³ā = ā2xā + xāĀ²; ln Ī³ā = xāĀ²
36
Identify the equation that is used to express the excess Gibbs free energy of a binary mixture, where its combinatorial part considers the composition, size and shape of the constituent molecules; and the residual part takes care of the intermolecular forces
Answer
D. UNIQUAC
37
The composition of a reaction mixture at the point where the Gibbs free energy is __________ is the equilibrium composition at the speciļ¬ed temperature and pressure.
Answer
A. minimum
38
Consider a reaction with standard free energy change ĪGĀ° = 200 kJ/kmol. Choose the most appropriate statement regarding the feasibility of this reaction.
Answer
C. Reaction may or may not be possible
39
Consider two species a and b. The partial molar enthalpy of species a in the binary mixture is = + , where and are the mole fractions of species a and b, respectively. Determine the partial molar enthalpy of species a at inļ¬nite dilution.
Answer
A. ā50
40
The term representing the net energy cost for a system created at a constant environmental temperature from a negligible initial volume after subtracting what the environment automatically supplied
Answer
D. Gibbs free energy
41
Critical thickness of insulation of a spherical shell is given by
Answer
D. 2k/h
42
The heat conduction in a composite slab consist of two materials as shown in figure. Which of the following statement is true if the thermal conductivities of the materials are kā and kā respectively
Answer
A. kā > kā
43
The distance from the leading edge of a flat plate at which transition occurs for water flowing at 1 m/s is (transition Reynolds number = 5 Ć 10āµ and kinematic viscosity Ī½ = 0.858 Ć 10ā»ā¶ mĀ²/s)
Answer
D. 0.43 m
44
The ratio of the thickness of thermal boundary layer to the thickness of hydro dynamic boundary layer is equal to (Prandtl number)āæ, where n is
Answer
B. ā1/3
45
Consider two black bodies with surfaces sā (area = 1 mĀ²) and sā (area = 6 mĀ²). They exchange heat only by radiation. If 60% of energy emitted by sā is received by sā, the fraction emitted by sā that is received by sā is
Answer
B. 0.1
46
Which of the following statements are true in the case of an ideal black body? (P) The emissivity of black body radiation is 1. (Q) The radiation emitted by a black body is of diļ¬erent wavelengths lying in regions of ultraviolet, visible and infrared (R) The transmittivity of black body is 1. (S) The lack body radiation curve at diļ¬erent temperature peaks at a wavelength is directly proportional to temperature
Answer
B. P and Q only
47
For turbulent flow in a pipe, assuming Seider-Tate correlation is valid, the heat transfer coefficient varies with the pipe diameter D as
Answer
D. Dā»ā°Ā·Ā²
48
A copper ball of 5 cm diameter at 300Ā°C is suddenly immersed in water at 30Ā°C. It cools down to 150Ā°C in 70s. It is then reheated to the initial temperature of 300Ā°C and suddenly exposed to air at 30Ā°C where it cools down to 150Ā°C in 200s. The diļ¬erence in cooling time is due to
Answer
C. Larger heat transfer coeļ¬cient of water
49
An electrically heated element is submerged in a pool of water at its saturation temperature. As the temperature of the element increases the Leidenfrost point is observed at
Answer
C. In the stable ļ¬lm boiling regime
50
A current of 200 A passes through a stainless-steel wire [k = 19 W/(mĀ·Ā°C)], 2 mm in diameter, resistance 0.1 Ī© and length 1 m. The wire is submerged in liquid at 110Ā°C with convection coefficient 4 kW/(mĀ²Ā·Ā°C). The centre temperature is
Answer
C. 274 Ā°C
51
In the case of mass transfer between two phases in contact, when the two phases attain equilibrium
Answer
D. Chemical potential of the components will be identical in both the phases
52
The concentration distribution for diļ¬usion of A through stagnant B under steady state is
Answer
B. logarithmic
53
Pick out incorrect statement from the following
Answer
C. At dew point, dry bulb temperature is greater than wet bulb temperature
54
In the case of simultaneous heat and mass transfer occurring in boundary layer ļ¬ow, the temperature and concentration proļ¬les are identical when
Answer
A. Lewis number = 1
55
Which of the following dryers is suitable for drying a feed in the form of solution into a dried particulate product in a single operation?
Answer
B. Spray drier
56
Which of the following is true in the case of solvents used in liquid- liquid extraction?
Answer
A. No separation is possible when selectivity is equal to one
57
Which of the following factors are favourable for leaching operation?
Answer
C. Low viscosity of the solvent used
58
In the case of absorption of solute from gas phase to liquid phase, if the solute is readily soluble in the liquid
Answer
B. Mass transfer is gas phase controlled
59
Which of the following is applicable to chemical adsorption?
Answer
C. Heat of adsorption is of the order of heat of reaction
60
Identify correct statement out of the following.
Answer
B. As reļ¬ux ratio increases, slope of operating line increases
61
Match the process in Group I with the catalyst in Group II Group I Group II P. Fischer-Tropsch Synthesis I Nickel Q. Formaldehyde from methanol II. R. Hydrogenation of vegetable oil III. Silver S. Dehydrogenation of Ethyl benzene IV. Cobalt
Answer
C. P-IV, Q-III, R-I, S-II
62
In petroleum reļ¬ning, catalytic reforming is used to convert
Answer
A. paraļ¬ns and naphthenes to aromatics
63
Match the polymer in Group I to the polymer characteristics in Group II Group I Group II P. Polyethylene I. Elastomer Q. Phenol-formaldehyde II. Fiber R. Polyisoprene III. Thermoplastic S. Polyester IV. Thermosetting
Answer
A. P-III, Q-IV, R-I, S-II
64
Which one of the following sequences is arranged according to increasing caloriļ¬c value?
Answer
C. Producer gas, water gas, natural gas
65
Hydrotreating is used for
Answer
D. Removal of sulphur and nitrogen from petroleum fraction
66
For making superphosphate by acidulation of phosphate rock, use of nitric acid is desirable, because
Answer
Question Cancelled
67
The active component of catalyst used in steam reforming of methane to produce synthesis gas is
Answer
C. nickel
68
Match the product in Group I to the raw material in Group II Group I Group II P. Ethylene 1. Natural gas Q. Methanol 2. Synthesis gas R. Phthalic anhydride 3. Naphtha 4. Naphthalene
Answer
D. P-3, Q-2, R-4
69
Which of the following is detergent?
Answer
B. Alkyl benzene sulphonate
70
Which of the following is not employed in the commercial production of linear PVC?
Answer
D. Condensation polymerization
71
Methanator is used in the ammonia plant for _____________.
Answer
C. Conversion of oxides of carbon to methane
72
Fertilizer produced during soda ash manufacture by dual process is ammonium
Answer
B. Chloride
73
is the chemical formula of _________ phosphoric acid.
Answer
A. Ortho
74
Which of the following is desirable in gasoline but undersirable in kerosene?
Answer
C. Aromatics
75
Match each of the polymers in Group I with raw material in Group II, from which they are made. Group I Group II P. Polyester I. Ethylene Glycol Q. Polyamide II. Adipic acid R. Viscose Rayon III. Cellulose S. Epoxy resin IV. Bisphenol.
Answer
A. P-I, Q-II, R-III, S-IV
76
Styrene is produced from ethyl benzene by the process of
Answer
B. Dehydrogenation
77
Which process is widely used to treat all types of woods to pulp?
Answer
D. Kraft
78
Nylon 66 is so named because
Answer
B. The number of carbon atoms between two nitrogen atoms are 6
79
The commonly used solvent in supercritical extraction is
Answer
D. Carbon dioxide
80
Commercially, ethylene is produced from naphtha by
Answer
B. Thermal cracking
81
Which among the following represents dynamic characteristics of an instrument?
Answer
C. Speed of response and lag
82
Which of the following thermocouples are used for high temperature measurement?
Answer
C. Platinum-Platinum, 13% rhodium
83
Which of the following regarding the response of manometers for a step change is correct
Answer
B. Manometers have underdamped response
84
The law stated as "the algebraic sum of the thermal emf's in a circuit composed of any number of dissimilar metals is zero, if all the circuit is at a uniform temperature" is called as
Answer
D. Law of intermediate metals
85
The inverse Laplace transform of the function F(s) = 1/[s(s+1)] given below is
Answer
A. 1āeā»įµ
86
In an on/oļ¬ controller the gain Kc is made
Answer
A. Very high
87
Which of the following statement is true regarding a PI controller?
Answer
B. order of response increases and oļ¬set is eliminated
88
An explosion in which reaction front moves at a speed greater than the speed of sound in an unreacted medium is called
Answer
D. Detonation
89
Class E ļ¬re is produced due to
Answer
D. Electrical apparatus
90
The degree to which an instrument indicate the changes in measured variable without dynamic error is called
Answer
A. Fidelity
91
Trickling ļ¬lter is an
Answer
C. Aerobic attached growth process
92
Blue Baby syndrome is due to the presence of excess _______ in drinking water.
Answer
D. Nitrates
93
BOD is used as a characteristic of
Answer
Question Cancelled
94
The angle between the solar collector surface plane and the horizontal plane is called
Answer
D. Tilt angle
95
Main product obtained from fermentation of biomass is
Answer
Question Cancelled
96
Permanent hardness of water can be removed by
Answer
D. Ion exchange
97
Electrodialysis removes
Answer
B. Dissolved solids from water
98
The permissible pH of drinking water is
Answer
B. 6.5-8.5
99
Which of the following is not a method of disinfection of water?
Answer
D. Filtration
100
What is the power in wind if wind velocity is 20 m/s and blade length is 60 m? Assume air density 1.23 kg/mĀ³.
Answer
A. 55.64 MW
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