| Post Name | Chemical Inspector/Technical Assistant (Chemical) - Factories And Boilers |
|---|---|
| Question Paper Code | 057/2025/OL |
| Category Code | 143/2024 |
| Date of Test | 24 June 2025 |
| Exam Type | Online Examination |
| Total Questions | 100 |
1
The temperature in Fahrenheit scale corresponding to 253 K
Answer
A. -4Ā°F
2
A gas is conļ¬ned in a cylinder by a piston. The initial pressure of the gas is 7 bar and the volume is 0.1 . The piston is held in place by latches in the cylinder wall. The whole apparatus is placed in a total vacuum. What can you say about the energy change of the apparatus if the retaining latches are removed so that the gas suddenly expands to double its volume?
Answer
C. Remain unchanged
3
From the following list, identify the properties which are equal in both vapour and liquid phases at equilibrium P. Density Q. Temperature R. Chemical potential S. Enthalpy
Answer
B. Q and R only
4
A gas obeying van der Waal's equation (Cv = 2/3 R) is expanded isothermally to double its original volume. After the expansion the value of Cv will be
Answer
C. 2/3 R
5
At a given temperature and pressure, a liquid mixture of benzene and toluene is in equilibrium with its vapor. The available degrees of freedom are
Answer
C. 2
6
For a pure liquid, the rate of change of vapor pressure with temperature is 0.1 bar/K in the temperature range of 300 to 350 K. If the boiling point of the liquid at 2 bar is 320 K, the temperature (in K) at which it will boil at 1 bar is
Answer
A. 310
7
At constant temperature and pressure the molar density of a binary mixture is given by S = 1 + xā, where xā is the mole fraction of component 2. The partial molar volume at infinite dilution for component 1 is
Answer
D. 0.75
8
Which among the following equation is associated with second law of thermodynamics
Answer
C. dQ = TdS
9
For liquids the volume expansivity (Ī²) is equal to
Answer
B. (1/V)(āV/āT)ā
10
All gases, when compared at the same reduced temperature and reduced pressure, deviates from the ideal gas behaviour to about the same degree. This concept is called
Answer
C. Theorem of correspondence states
11
A pump is located between two stations a an b in a chemical plant. In the entire pumping system, the loss due to friction is estimated as 10 ft. lbf/lb. If work done by the pump is 100 ft. lbf/lb, estimate the pump eļ¬ciency
Answer
C. 90%
12
The discharge pressure shown by a pressure gauge in the outlet of the pump is 3 atm. Then the respective absolute pressure at the pump outlet will be
Answer
A. 4 atm
13
Bernoulli's equation without friction is
Answer
D. Pā/Ļ+vāĀ²/2+gZā=Pįµ/Ļ+vįµĀ²/2+gZįµ
14
An oil with a specific gravity of 0.887 flows through the pipe at 30 ftĀ³/min. The mass flow rate of the oil in the pipe is ___________ lb/h. (Take the density of the reference, water, as 1000 kg/mĀ³.)
Answer
B. 99675.74
15
The SI unit of viscosity is
Answer
C. kg/(mĀ·s)
16
Friction factor for turbulent ļ¬ow in a hydraulically smooth pipe
Answer
A. depends only on
17
Which of the following is the Hagen - Poiseulle equation?
Answer
D. Ī
18
Net Positive Suction Head (NPSH) of a centrifugal pump must be
Answer
C. greater than vapour pressure of liquid
19
A pipe of particular dimension with schedule number 80 is ___________ the pipe of same dimension with schedule number 40.
Answer
A. having higher thickness than
20
A tank has a water (speciļ¬c gravity=1) of 10 m high in a circular tank of 2 inch diameter. The top of the tank is opened and top surface of water is exposed to atmospheric air of 1 atm. What is pressure at the mid of the water level in the tank (i.e. at 5 m height)?
Answer
C. 1.48 atm
21
For the same volume, a cube does have _____________ times more surface area compared to a sphere.
Answer
C. 1.23
22
The work index of Bond's law is a measure of :
Answer
C. Grindability of a material under standard test conditions
23
For smooth roll crushers, the angle of nip typically ranges from
Answer
B. 16Ā° to 24Ā°
24
Which one of the following statements in NOT true?
Answer
A. Axial ļ¬ow impellers impose shear stress to the ļ¬uid, and are used to mix immiscible liquids
25
The formation of nuclei occurs in the presence of solid surfaces (such as the wall of container or pipe) other than those of crystals in the magma is known as
Answer
C. Heterogeneous nucleation
26
Which one of the following state is FALSE? In case of compressible cakes :
Answer
D. Compressibility index is zero
27
Which of the following mixer is used for free-ļ¬owing solids?
Answer
A. Ribbon blender
28
The maximum safe angle at which free-ļ¬owing bulk solids can be stored in a conical heap without collapsing is known as
Answer
A. Angle of repose
29
Thermal contact resistance of an interface depends on
Answer
D. All of the above 1, 2, 3
30
The dimensionless group that compares rate of heat transfer by bulk ļ¬ow and conduction
Answer
B. Peclet Number
31
Which of the following two statements are/is correct? Statement 1 : If a bubble nucleus is formed in the bulk of a superheated liquid, it is called homogeneous nucleation. Statement 2 : If a nucleus is formed on a hot surface or on a solid particle suspended in the superheated liquid, it is called heterogeneous nucleation.
Answer
A. Both statements 1 and 2 are correct
32
Which of the following is not true for a black body?
Answer
D. Spectral black body emissive power is given by Stefan- Boltzmann law
33
Suggest the most suitable heat exchanger for milk chilling and pasteurization in a diary plant
Answer
D. Plate Heat Exchanger
34
The cross sectional area of downtake generally varies from ____________ of the ļ¬ow area of tubes in a short tube vertical evaporator.
Answer
A. 50 to 100%
35
Under which condition can a double pipe heat exchanger replace a shell and tube heat exchanger?
Answer
C. For high pressure duties
36
Under which condition LMTD is not the correct mean temperature diļ¬erence to use?
Answer
D. All of the above (1, 2 and 3)
37
Economy of an evaporator system depends on
Answer
C. Both number of eļ¬ects and temperature of feed
38
The total radiation that leaves a surface per unit area per unit time is called
Answer
A. radiosity
39
For steady-state equimolar counter-diffusion of gases A and B, the value of N_A/(N_A + N_B) is:
Answer
D. ā
40
For absorbing a sparingly soluble gas in a liquid, mass transfer rate can be increased by
Answer
A. Increasing the liquid side mass transfer coeļ¬cient
41
In a cooling tower, the 'wet bulb temperature approach' is deļ¬ned as the diļ¬erence between the
Answer
C. wet-bulb temperature of inlet air and the exit water temperature
42
One hundred kg each of a solid feed containing 20% solute and 80% insoluble inerts is subjected to single stage leaching using one hundred kg of a pure solvent. After settling, 80 kg of clear solution is withdrawn as overļ¬ow. What is the inert to solution weight ratio in the underļ¬ow?
Answer
B. 2
43
A packed distillation column, with vapour having an average molecular weight of 45 kgĀ·molā»Ā¹, density of 2 kgĀ·mā»Ā³ and a molar flow rate of 0.1 kmolĀ·sā»Ā¹, has a flooding velocity of 0.15 mĀ·sā»Ā¹. The column is designed to operate at 60% of the flooding velocity. Which one of the following is the CORRECT value for the column diameter (in m)?
Answer
B. 10/āĻ
44
For a ļ¬xed degree of absorption by a ļ¬xed amount of solvent, with increase in gas rate, the number of transfer units
Answer
A. increases
45
Which one of the following is a favourable condition for the formation of an ideal break through curve?
Answer
D. Axial dispersion is negligible
46
500 kg feed containing 40% C is extracted with 400 kg of pure solvent B. 600 kg extract is formed analysing 25% C. The distribution coeļ¬cient corresponding to this concentration is
Answer
D. 1.5
47
Increasing the reļ¬ux ratio
Answer
C. increases the vapour boil-up
48
The number degrees of freedom for an azeotropic mixture in a two- component vapour -liquid equilibria is/are
Answer
B. One
49
Reaction with high activation energy are
Answer
A. Highly temperature sensitive
50
A mixture of 20% and 80% air is charged to a variable volume batch reactor at constant temperature and pressure in which is oxidised. The number of moles of produced per 100 moles of feed at 80% conversion of is
Answer
A. 13.3
51
The half-life of a ļ¬rst order liquid phase reaction is 30 minutes. Then the rate constant in is
Answer
B. 1.386
52
A liquid-phase reaction is to be carried out under isothermal conditions. The reaction rate as a function of conversion has been determined experimentally and is shown in the following ļ¬gure. What choice of reactor or combination of reactors will require the minimum overall reactor volume, if a conversion of 0.9 is desired?
Answer
D. PFR followed by a CSTR, followed by a PFR
53
A ļ¬rst order liquid phase reaction is taking place in two equal sized CSTRs connected in series. If the conversion from the ļ¬rst reactor is 40%, then the conversion from the second reactor is
Answer
B. 64
54
For a series of reaction A ākāā B ākāā C having kāāŖkā, the reaction system can be approximated as
Answer
C. A ākāā C
55
For the liquid phase parallel reactions The desire product is R. A higher selectivity of R will be achieved if the reaction is conducted at
Answer
D. High temperature in a PFR
56
A pulse tracer is introduced in an ideal CSTR (with a mean residence time Ļ) at time = 0. Determine the time taken for the exit concentration of the tracer to reach half of its initial value.
Answer
D. 0.693 Ļ
57
The substrate limiting microbial reaction, A ā R+C, is taking place with less food or very low substrate concentration. The rate constant (kāįµā) and order (n) of this reaction are, respectively.
Answer
A. kāįµā=k/CM; n=2
58
An isothermal pulse test is conducted on a reactor and the variation of the outlet tracer concentration with time is shown below: The mean residence time of ļ¬uid in reactor (in min) is
Answer
B. 7.5
59
Error calibration means that an industrial instrument has been especially calibrated.
Answer
C. against a suitable standard and its static error determined at a number of points of its scale
60
One of the desirable properties of thermocouples for industrial use is
Answer
A. Relatively large thermal emf
61
Which of the following eļ¬ects must be considered when using radiation receivers in a radiation pyrometer?
Answer
A. Reference - junction temperature eļ¬ect, distance eļ¬ect, absorbing - media eļ¬ect and emissivity eļ¬ect
62
A convenient unit for expressing very low absolute pressures is the micron.
Answer
B. A micron is 0.001 mm of mercury column absolute pressure at 32Ā°F
63
Diaphragm - Box system is for
Answer
D. Liquid-level measurements
64
The ļ¬rst order processes are characterized by i. Their capacity to store material, energy or momentum. ii. The resistance associated with the ļ¬ow of mass, energy or momentum in reaching the capacity. iii. Their ability to instantaneously reach equilibrium without any time lag.
Answer
C. Only i and ii
65
Which of the following best explains how a second-order system commonly arises in chemical engineering applications?
Answer
B. When a controller is added to a ļ¬rst order process
66
In a single-loop feedback control system, the overall transfer function for a change in set point C/R is given by:
Answer
A. G_CGāGā/(1+G_CGāGāH)
67
The Routh-Hurwitz criterion determines stability based on:
Answer
C. The number of sign changes in the ļ¬rst column of the Routh array
68
In a cascade control system, why is a proporational (P) controller commonly used for the secondary loop?
Answer
D. Because fast disturbance rejection is the main goal, and oļ¬set in the secondary loop is not critical
69
What is the unit of measuring radiation exposure, deļ¬ned as the energy ļ¬ux of unperturbed photon radiation?
Answer
B. Roentgen
70
How do you deļ¬ne the term 'solar constant'?
Answer
A. Amount of energy received per unit time per unit area perpendicular to the sun's direction
71
A surface coating helps to increase the absorption of a solar energy collected ___________ is a good coating material.
Answer
C. Black chrome
72
One of the major components of biomass is cellulose. What is cellulose?
Answer
C. A homopolysaccharide of glucose
73
Turbidity of water can be managed by using coagulants such as
Answer
A. Ferric sulphate
74
The BOD test is carried out in a wastewater sample by measuring the
Answer
C. Dissolved oxygen
75
The following method is one of the means of removing ammonia from wastewater
Answer
C. Nitriļ¬cation denitriļ¬cation
76
High levels of which of the following pollutants result in eļ¬ects such as headache, poor coordination visual and speech disturbances, coma and even death?
Answer
A. Carbon monoxide
77
When a ļ¬ammable liquid is spilled onto water and ignited, the type of ļ¬re is called?
Answer
B. Pool ļ¬re
78
Which of the following deļ¬nition best ļ¬ts the term hazard?
Answer
B. A situation that has the potential to cause harm to humans, the environment and property
79
which type of ļ¬re extinguisher is used for putting out electrical ļ¬res?
Answer
C. Class C
80
The full form of UVCE in the context of safety in chemical industries is
Answer
C. Unconļ¬ned vapour cloud explosion
81
Which of the following is used as promoter for pure vanadium pentoxide during the manufacture of sulphuric acid?
Answer
B. Potassium
82
Which among the following are not considered as raw materials for manufacture of phosphoric acid?
Answer
D. Concentrated nitric acid and phosphate rock
83
In LeBlanc process for the manufacture of soda ash, the raw materials are
Answer
A. Sodium sulphate and limestone
84
What is the primary goal of Kraft pulping process?
Answer
C. To separate lignin from cellulose
85
Aniline point test of an oil qualitatively indicates the ____________ content of an oil.
Answer
C. Aromatic
86
What is the main aim of desalting crude oil?
Answer
D. To prevent corrosion in reļ¬ning equipment
87
Temperature range in all catalytic cracking operations lies in the range of
Answer
D. 450-510 Ā°C
88
The main reaction in the reforming is
Answer
B. Dehydrogenation of naphthenes
89
Which of the following is not used for alkylation processes?
Answer
C. Hydrochloric acid
90
What are the monomers used in the production of Nylon-6,6?
Answer
B. Adipic acid and Hexamethylene diamine
91
The inventory of raw materials that forms part of the working capital typically represents approximately _____________ months' worth of raw materials, assessed at delivery prices.
Answer
C. One
92
Among the options presented, the depreciation calculation using the __________ method yields the highest value.
Answer
B. Diminishing balance
93
The ļ¬xed charges associated with a chemical plant do not encompass the
Answer
D. Interest on borrowed capital
94
What is the anticipated return on investment for a project involving an investment of Rs. 30 lakhs, which generates annual savings of Rs. 10.5 lakhs and incurs annual operating cost of Rs. 1.5 lakhs?
Answer
A. 30 percent
95
The diļ¬erence between the maximum time allotted and the actual time required to complete a task in a project is referred to as
Answer
B. Total ļ¬oat
96
Which of the following does not constitute an objective of ļ¬nancial statements?
Answer
A. To ascertain income tax liability
97
The collection of all products and items that a speciļ¬c seller provides for sale is referred to as
Answer
C. Product mix
98
Which of the following ļ¬nancial analysis methods is employed to assess the proļ¬tability of a project?
Answer
D. All of the above
99
Which of these layouts is the most appropriate for the processing of sugar derived from sugar beets or sugar cane?
Answer
A. Process-oriented layout
100
Cost of utilities in the operations of a chemical plant comes under the
Answer
B. Direct production cost
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