Assam JLEE 2025 Question Paper Chemical Engineering

Section – Mathematics
1 2 3 𝑛
1. logn →∞ (1−𝑛2 + 1−𝑛2 + 1−𝑛2 ….. + 1−𝑛2) is equal to
1
A) 1 B) 2
1
C) − 2 D) 2

2. Find the area of the region bounded by the parabola y2 = 16x and the line x = 4x.
A) 12 sq. unit B) 256/5 sq. unit
C) 128/3 sq. unit D) 125 sq. unit
1−𝑖𝑥
3. If 1+𝑖𝑥 = a – ib, then a2 + b2 equals to
1
A) 𝑥 B) 1
C) x D) x2
1 1 1
4. If 8! + 9! = 10! , then x equals to
A) 100 B) 64
C) 80 D) 121

5. The number of diagonals that can be drawn by joining the vertices of an octagon is
A) 28 B) 16
C) 20 D) 24

6. Find the coefficient of a6b3 in the expansion of (a + 2b)9.
A) 144 B) 256
C) 444 D) 672
⨅ 2⨅ 4⨅ 8⨅
7. tan 3 + 2tan 3 + 4tan 3 + 8tan 3 is
A) √3 B) 2√3
C) √5 D) -5√3

8. Find the value of k for which the line (k−3) x− (4 − k2) y−6 = 0 is parallel to the x-axis.
A) 2 B) 3
C) 4 D) 6

9. The curve represented by x = 2(cost + sint), y = 5(cost − sint) is
A) a circle B) a parabola
C) a hyperbola D) an ellipse

10. If the 5th term of an AP is 11 and the 9th term is 7, then the 14th term is
A) -1 B) 2
C) 1 D) 0

11. The polar form of the complex number −1 + i is
3⨅ 3⨅ 1 3⨅ 3⨅
A) √2 (cos 4 + isin 4 ) B) √2 (cos 4 + isin 4 )
⨅ ⨅ 1 ⨅ ⨅
C) √2 (cos4 + isin4 ) D) √2 (cos4 + isin4 )

1 −2 3
12. If the matrix 1 2 1 is singular, then the value of x is
𝑥 2 −3
A) -1 B) 0
C) 1 D) 2

13. Two cylindrical jars have their radii in the ratio 1: 3 and heights in the ratio 2: 3. Then the ratio of their
volume is
A) 2:27 B) 4:9
C) 3:16 D) 2:9

14. If 2n – 2n-1 = 64, then the value of n is
A) 4 B) 8
C) 7 D) 9

15. The sum up to n terms of the series 1 + 3 + 9 + 27 + ⋯ is 364. Then the value of n is
A) 5 B) 6
C) 7 D) 9
1
16. If x = 3 + √8 then the value of x2 + 𝑥 2 .
A) 32 B) 34
C) 38 D) 42

17. A right-angled triangle is formed by the line 4x + 3y = 124 and the coordinate axes. The area of the
triangle in square units is
A) 2 B) 3
C) 4 D) 6

18. The range of f(x)=1 + 3cos 2x is
A) [-2,4] B) [2,3]
C) [2,4] D) [-1,1]

19. ∑10 3
𝑛=1 𝑛 =
A) 972 B) 2025
C) 3025 D) 4650

20. The 3rd term of a geometric progression is 4. The product of the first five terms is
A) 43 B) 44
C) 45 D) None of the above

21. Find the value of a for which the line (4 − a2) x − (a − 3) y + 6 = 0 is parallel to the y - axis.
A) 3 B) 4
C) 7 D) 1

22. If the point P(x, y) is equidistant from the points A (a + b, b − a) and B (a − b, a + b), then
A) ax = by B) bx = ay
2 2
C) x – y = 2 (ax + by) D) ax2 = by2
2
23. The coefficient of x15 in the expansion of (x2 + 𝑥 )15 is
A) 15C728 B) 15C827

C) 15C525 D) 15C10210

24. If (n + 1)! = 12(n − 1)! then n is equal to
A) 3 B) 4
C) 5 D) 8
1−𝑖𝑥
25. If 1+𝑖𝑥 = A + iB, then A2 + B2 equals to
A) -1 B) x2
C) -x2 D) 1

26. Find the area of the region bounded by the line 2y + x = 8, the x - axis and the lines x = 2 and x = 4.
A) 4 sq. unit B) 5 sq. unit
C) 6 sq. unit D) 9 sq. unit

27. Evaluate ∫√1 − 𝑠𝑖𝑛2𝑥 dx
A) sinx + cosx + c B) sinx – cosx + c
1 1
C) 2 sin2x + c D) - 2 cos2x + c
𝑑𝑦
28. If y = √𝑠𝑖𝑛𝑥 + 𝑦, then 𝑑𝑥 =
𝑐𝑜𝑠𝑥 𝑠𝑖𝑛𝑥
A) 1−2𝑦 B) 2𝑦−1
𝑠𝑖𝑛𝑥 𝑐𝑜𝑠𝑥
C) 1−2𝑦 D) 2𝑦−1

1
(2𝑥 2 + 3), 𝑥 ≤ 1
5
29. The point(s) of discontinuity of the function g (x) = {6 − 5𝑥, 1 < 𝑥 < 3
𝑥 − 3, 𝑥≥3
A) 1 B) 3
C) 1, 3 D) 0, 1, 3

30. Let f(x) = x + 2, g(x) = x2 + 2, then g(f(x)) =
A) x2 – 4x + 5 B) x2 + 4x + 6
C) (x2 + 2)(x + 2) D) x2 - 4

Section – Basic of Computer Science

31. Which of the following values is the correct value of this hexadecimal code ABCDEF?
A) 11259375 B) 11259379
C) 11259372 D) 11259371

31. The part of the OS that manages the CPU, memory and I/O devices is called
A) Compiler B) Kernel
C) Shell D) Driver

32. What is the function of the "ATTRIB" command in DOS?
A) Change file attributes B) Display file contents
D) Rename files C) Remove hidden files

33. A key difference between LAN and WAN is
A) WAN is faster than LAN
B) LAN operates in a small geographic area, while WAN covers a broader area
C) WAN does not require any cables
D) LAN uses more advanced technology than WAN

34. Which of the following is the default slide layout in PowerPoint?
A) Title Slide B) Title and Content
C) Blank D) Two Content

35. In MS Word, what is the maximum number of columns you can insert in a table?
A) 35 B) 63
C) 100 D) 255

36. Which memory stores the most frequently used instructions to increase processing speed?
A) ROM B) RAM
C) Cache D) Secondary storage

37. How do you find the 2's complement of a binary number?
A) Invert all bits B) Invert all bits and add 1
C) Add 1 D) Change the sign bit

38. Which command in DOS is used to display information about the system's hardware and software
configuration?
A) CONFIG B) SYSTEMINFO
C) INFO D) HARDWARE

39. Which of the following is an example of a device used to connect different LAN to form a WAN?
A) Hub B) Router
C) Switch D) Access Point

40. What does the "Mail Merge" feature in MS Word do?
A) Merges multiple documents into one
B) Allows you to combine a document with a data source to create personalized letters
or labels

C) Merges different text styles into one document
D) Combines multiple email messages into one

Section – Engineering Graphics

41. A scale where the drawing is made smaller than the actual object is called a
A) Full scale B) Enlarged scale
C) Reduced scale D) Diagonal scale

42. Which of the following is a key requirement of dimensioning?
A) To make the drawing look more complex
B) To provide all necessary information for manufacturing or construction
C) To fill empty spaces on the drawing sheet
D) To indicate the color of the object

43. The rectangular method can be used for the construction of which of the following conic sections?
A) Ellipse and Parabola only
B) Parabola and Hyperbola only
C) Ellipse and Hyperbola only
D) Ellipse, Parabola, and Hyperbola

44. If a point is located in the first quadrant, its projection on the Horizontal Plane (HP) will be
A) Above the XY line
B) Below the XY line
C) On the XY line
D) Any of the above depending on the Vertical Plane (VP)

45. When a straight line is perpendicular to one reference plane and parallel to the other, its projection on
the plane to which it is perpendicular will be
A) A line of true length
B) A line shorter than true length
C) A point
D) A line longer than true length

46. Isometric projection is a type of
A) Orthographic projection
B) Axonometric projection (specifically, a type of orthographic axonometric
projection)
C) Perspective projection
D) Oblique projection

47. A diagonal scale is used to measure
A) Only two units or a unit and its sub-unit
B) Only angles
C) Up to three units (e.g., meters, decimetres, and centimetres) or a unit and its two
sub-divisions
D) Curved lines accurately

48. The concentric circle method is specifically used for the construction of which conic section?
A) Parabola

B) Hyperbola
C) Ellipse
D) All conic sections

49. What is a key difference between first angle and third angle projection symbols?
A) The arrangement of the circle and truncated cone views
B) The type of lines used
C) The scale indicated
D) The number of views shown

50. The process of creating isometric views from orthographic projections involves
A) Projecting views at 90 degrees to each other
B) Representing the 3D object on a 2D plane showing three faces
C) Using only one principal view
D) Scaling down all dimensions by half

Section – Chemical Engineering

51. Crushing efficiency is the ratio of
A) The energy absorbed by the solid to the surface energy created by the crushing
B) The energy absorbed by the solid to that of the machine
C) Surface energy created by the crushing to the energy absorbed by the solid
D) The energy absorbed by the solid to the surface energy created by the crushing

52. In a forward feed multiple effect evaporator unit
A) no pump is required to withdraw the product from the last effect
B) viscosity of liquid is highest in first effect
C) transfer from effect to effect is done by pumps
D) none of these

53. Selection of material for thermocouple depends on the
A) Depth of immersion in the hot fluid
B) Pressure and velocity condition of the fluid whose temperature is to be measured
C) Minimum and maximum temperature
D) None of these

54. Ideal refrigeration cycle is
A) Same as Carnot cycle
B) Dependent on the refrigerant’s properties
C) Same as reverse Carnot cycle
D) The least efficient of all refrigeration processes

55. 25 per cent segmented baffle means that the baffle
A) Height is 25% of the I.D. of the shell
B) Spacing is 75% of the height
C) Width is 25% of its height
D) Height is 75% of the I.D. of the shell

56. In a shell and tube heat exchanger
A) the temperature drop is inversely proportional to the resistance across which the
drop occurs
B) there is no relationship between temperature drop and resistance
C) the relationship is complicated
D) the temperature drops in tube fluids and the wall are proportional to individual
resistances

57. Degree of freedom, when a system contains a gaseous mixture of nitrogen and ammonia, is
A) 1 B) 4
C) 3 D) 2

58. The velocity distribution in the turbulent boundary layer follows
A) Straight line law B) Logarithmic law
C) Hyperbolic law D) Parabolic law

59. During size reduction, the optimum speed of ball mill must be
A) 50–75% of the critical speed B) 30–55% of critical speed
C) more than 90% of critical speed D) 70–85% of critical speed

60. For steady flow and constant value of conductivity, the temperature distribution for a plane wall is
A) parabolic B) cubic
C) logarithmic D) linear

61. A 10 m³ CSTR is used to decompose a dilute solution of A. The decomposition is irreversible with a first
order rate constant of 3.45 hr⁻¹. If 95% decomposition of A is desired, the required feed rate is
A) 1.35 m³/hr B) 1.5 m³/hr
C) 2.5 m³/hr D) 1.82 m³/hr

62. In the design of the bubble cap tray of a distillation column to give stable operation and even vapor
distribution
A) the dimensionless ratio of liquid gradient to pressure drop head caused by the
bubble cap assembly should be less than 0.4
B) tendency towards stable operation is increased by increasing the skirt clearance of
the caps, lowering the rate of liquid flow per unit plate width or increasing the spacing
between the caps
C) pressure drop due to the caps and the slots and the static submergence should be
as high as practicable for reasonable operation
D) Isobaric

63. Contact process replaced Lead chamber process in the manufacture of sulphuric acid due to
A) quite cheaper and easier to control
B) acid of any strength can be prepared by this method
C) sulphuric acid obtained by this method is pure and concentrated
D) all of these

64. The type of polymer obtained by decomposition of diazomethane in cold ether solution in the presence
of platinum catalyst is
A) Crosslinked polyethylene B) HDPE
C) LLDPE D) LDPE

65. By German Tower process, styrene is polymerized through
A) Suspension polymerization B) Solution polymerization
C) Emulsion polymerization D) Bulk polymerization

66. Temperature during hydrogenation of oil should not be more than 200°C, otherwise it will result in
A) Hydrogen embrittlement B) Sintering of porous catalyst
C) Pyrolysis of oil D) All of these

67. When a saturated sodium chloride solution is electrolyzed using graphite anode and steel cathode, the
products are
A) Hydrogen, chlorine and sodium hydroxide solution
B) Hydrogen and oxygen
C) Sodium metal and chloride

D) Hydrogen, chlorine and soda ash

68. The Sieder–Tate correlation for heat transfer in turbulent flow in a pipe gives Nu ∝ Re⁰·⁸. Assuming that
this relation is valid, the heat transfer coefficient varies with pipe diameter (D) as
A) D⁻¹·⁸ B) D⁰·²
C) D⁻⁰·² D) D¹·⁸

69. A composite wall consists of two plates A and B placed in series normal to the flow of heat. The thermal
conductivities and specific heat capacities of plates A & B are kA, kB and CpA , CpB respectively. Plate B has
twice the thickness of plate A. At steady state, the temperature difference across plate A will be greater than
that across plate B when
A) CpA > CpB B) kA < 0.5kB
C) CpA < CpB D) kA > 2kB

70. At 750 K and 1 atm, the approximate value of the Schmidt number for air is
A) 1 B) 0.1
C) 0.01 D) 10

71. 80 kg of Na₂SO₄ (molecular weight = 142) is present in 330 kg of an aqueous solution. The solution is
cooled such that 80 kg of Na₂SO₄·10H₂O crystals separate out. The weight fraction of Na₂SO₄ in the remaining
solution is
A) 0.00 B) 0.18
C) 0.24 D) 1.00

72. Which is the correct statement from the following statements on the Arrhenius model of the rate constant
k = Ae⁻ᴱ/ᴿᵀ?
A) For a given reaction, the % change of k with respect to temperature is higher at
lower temperatures
B) For two reactions 1 and 2 if A₁ = A₂ and E₁ > E₂, then k₁(T₁) > k₂(T₂)
C) A is always dimensionless
D) The % change of k with respect to temperature is higher for higher A

73. In a binary liquid solution of components A and B, if component A exhibits positive deviation from Raoult’s
law, then component B
A) Obeys Raoult’s law
B) Exhibits negative deviation from Raoult’s law
C) Exhibits positive deviation from Raoult’s law
D) May exhibit either positive or negative deviation from Raoult’s law

74. Ordinary mercury-in-glass thermometer works on the principle of
A) Increase of vapour pressure with increase in temperature
B) Increase of electrical resistance with increase in temperature
C) Volumetric expansion of mercury with increase in temperature
D) Decrease of vapour pressure with increase in temperature

75. How is the resistance to solvent flow determined?
A) By measuring pore size distribution
B) By calculating water permeability

C) By measuring amount of air passing
D) By measuring the volume of solvent passed after a certain time

76. The selection of membrane does not depend on which property?
A) Pore size distribution
B) Film thickness formed
C) Permeability
D) Water permeability

77. A “Calming section” before the liquid flows into the downcomer is provided to
A) reduce the discharge fluctuation
B) ensure better vapour–liquid contact
C) permit release of entrained vapour in the liquid
D) cool the liquid before it flows down

78. Pour point of Bombay high crude oil is
A) 18°C B) 30°C
C) −18°C D) −50°C

79. Aniline point of an oil is the lowest temperature at which the oil is completely miscible with an equal
volume of aniline. High aniline point indicates that the fuel
A) Has very poor ignition quality B) Has low diesel index
C) Is highly paraffinic D) Is highly aromatic

80. In the atmospheric distillation of crude petroleum
A) The content of nitrogen decreases from lighter fraction to heavier ones, with the
residue having the lowest concentration of nitrogen
B) The content of sulphur decreases from lighter fraction to heavier ones, with the
residue having the lowest concentration of sulphur
C) The content of sulphur increases from lighter fraction to heavier ones, with the
residue having the highest concentration of sulphur
D) None of the above

81. An Orsat analysis of the combustion products of a hydrocarbon liquid fuel gives the following results: CO₂
= 10%, CO = 0.5%, O₂ = 5% and N₂ = 76% (by vol). The C/H ratio (by weight) of the liquid fuel is
A) 1.06
B) 6.86
C) 3.18
D) Cannot be determined due to inadequate information

82. Zeolite softening process removes both temporary and permanent hardness of water. In this process the
calcium and magnesium present in water are precipitated as
A) Insoluble carbonates B) Insoluble sulphates
C) Insoluble chlorides D) Insoluble nitrates

83. In a double pipe (concentric) heat exchanger, the hydraulic radius for heat transfer in fluid flowing through
the annulus would be
A) same as that for tube flow

B) less than that for tube flow
C) more than that for tube flow
D) (Dₒ − Dᵢ)/4, where Dᵢ and Dₒ are inner diameter of inner and outer pipes respectively

84. Comparing sulphate process with sulphite process, we find that
A) both temperature and pressure in former is less than that in latter
B) both temperature and pressure in former is more than that in latter
C) temperature is more in the former whereas pressure is more in the latter
D) pressure is more in the former whereas temperature is less in the latter

85. A space time of 3 hours for a reactor means that
A) The time required to process one reactor volume of feed (measured at specified
conditions) is 3 hours
B) Three reactor volumes of feed can be processed per hour
C) It takes three hours to dump the entire volume of the reactor with feed
D) Conversion is one per cent after three hours

86. In the case of shell and tube heat exchanger, the logarithmic mean temperature difference
A) Is always less than arithmetic average value
B) Is always more than arithmetic mean value and geometric mean value
C) Is always less than arithmetic mean value but more than geometric mean value
D) May be either more or less than geometric mean and arithmetic mean value
depending upon whether the flow of stream is co-current or counter-current

87. Nylon 6–6 is manufactured from
A) hexamethylene diamine and adipic acid
B) hexamethylene diamine and maleic anhydride
C) caprolactam
D) dimethyl terephthalate and ethylene glycol

88. Sorting classifier uses a sink-and-float method to separate particles of differing densities. The separation
A) Depends on the particle size
B) Depends on the difference in terminal velocities
C) Depends on the difference in the densities of the particles
D) Depends on the centrifugal force

89. Compressed air from a container at normal temperature is allowed to escape suddenly through a hole
made in the container; the air inside
A) Starts becoming hotter
B) Starts becoming cooler
C) Remains at the same temperature
D) May become hotter or cooler depending upon the amount of water vapour present
90. For the irreversible unimolecular-type first-order reaction
A) The fractional conversion at any time is same for constant volume systems and
variable volume systems
B) The fractional conversion at any time is more for constant volume systems than
variable-volume systems

C) The fractional conversion at any time is less for constant volume systems than
variable-volume systems
D) The concentration of reactant at any time is same for constant-volume systems and
variable-volume systems

91. Which of the following petroleum products has minimum flash point?
A) Gasoline B) Kerosene
C) High speed diesel oil D) Fuel oil

92. If the frequency of the stirrer in a mixing tank is increased by a factor of 2 while all other parameters are
kept constant, by what factor is the power requirement increased (high Reynolds number)?
A) 4 B) 8
C) 16 D) 32

93. A perfectly insulated container of volume V is divided into two equal halves by a partition. One side is
under vacuum while the other side has one mole of an ideal gas with constant heat capacity at 298 K. If the
partition is broken, the final temperature of the gas in the container is
A) will be greater than 298 K B) will be 298 K
C) will be less than 298 K D) cannot be determined

94. A process flow sheet analysis results in the degree of freedom having a value of −2. Which one of the
following steps must be carried out?
A) Identify and add two independent equations from process model
B) Remove two equations that have been wrongly assumed to be independent
C) Assign values of two variables in the process
D) Assign value to one variable and remove one equation that was wrongly assumed
to be independent

95. The most efficient equipment for removal of sub-micron dust particles from blast furnace gas is

A) Electrostatic precipitator B) Gravity settling chamber
C) Venturi scrubber D) Cyclone separator

96. A space time of 3 hours for a reactor means that
A) The time required to process one reactor volume of feed (measured at specified
conditions) is 3 hours
B) Three reactor volumes of feed can be processed per hour
C) It takes three hours to dump the entire volume of the reactor with feed
D) Conversion is one per cent after three hours

97. Black liquor is converted into the white liquor by
A) Multi-effect evaporation only
B) Selective liquid extraction
C) Extractive distillation
D) Evaporation and burning the concentrate followed by causticisation of products

98. XLPE is the trade name of
A) Cross-linked polyethylene B) High density polyethylene
C) Linear low density polyethylene D) Low density polyethylene

99. The critical radius for curved insulation
A) Decreases with decreasing insulation thickness
B) Is independent of insulation thickness
C) Depends on the thermal conductivity of insulating material
D) Increases with decreasing insulation thickness

100. Applying a pressure drop across a capillary results in a volumetric flow rate Q under laminar flow
conditions. The flow rate, for the same pressure drop, in a capillary of the same length but half the radius is
A) Q/2 B) Q/16
C) Q/8 D) Q/4