WorksheetsMock Model Exam for Exit Exam 2025
Total questions: 143
Worksheet time: 1hrs 12mins
What is the main reason for using reinforcement rings in large shell designs?
To increase internal pressure
To prevent buckling and structural failure
To improve heat transfer efficiency
To reduce manufacturing costs
Why are baffles used in heat exchangers?
To increase fluid velocity
To reduce heat loss
To prevent corrosion
None
Which factor is most critical when designing a shell-and-tube heat exchanger?
Tube material conductivity
Number of tubes
Shell diameter
Fluid viscosity
What is the primary reason for using longitudinal baffles in shell-and-tube heat exchangers?
To minimize flow velocity
To increase turbulence and enhance heat transfer
To eliminate cross-flow interactions
To reduce shell fouling
Which code is most commonly used for the design of pressure vessels?
ASME Section VIII
ASTM D2000
ISO 14001
API 650
What is the primary purpose of stiffeners in externally pressurized pressure vessels?
To improve thermal conductivity
To reinforce structural integrity against buckling
To control fluid velocity inside the vessel
To optimize heat exchanger efficiency
Which head type is most commonly used for high-pressure internal vessel applications due to its strength?
Flat head
Ellipsoidal head
Hemispherical head
Torispherical head
Which reactor type is best suited for highly exothermic reactions requiring efficient heat removal?
PFR
Batch reactor
Fluidized bed reactor
CSTR
Enzymes are best described as:
Hormones
Structural proteins
Biological catalysts
Energy carriers
The Monod equation relates microbial growth rate to:
Substrate concentration
Temperature
Oxygen concentration
Time
Which of the following is used to sterilize fermentation media?
UV light
Autoclaving
Filtration
Alcohol
In aerobic fermentation, the terminal electron acceptor is:
Nitrate
Oxygen
Sulfate
Carbon dioxide
A chemostat is an example of:
Batch reactor
Fed-batch reactor
Continuous stirred tank reactor (CSTR)
Plug flow reactor
The lag phase in microbial growth curve is characterized by:
Maximum cell division
Cell death
Adaptation without division
Nutrient depletion
The pH in a bioreactor is typically controlled using:
Buffers
Enzymes
Antibiotics
Inhibitors
Fermentation used to produce ethanol from glucose is:
Aerobic
Anaerobic
Phototrophic
Lithotrophic
The specific growth rate (μ) is defined as:
Biomass/time
Time/biomass
dX/dt
(1/X)·(dX/dt)
What is the order of a reaction whose rate is independent of the concentration of reactants?
First order
Second order
Zero order
Third order
The unit of rate constant for a second-order reaction is:
s⁻¹
L/mol·s
mol/L·s
L²/mol²·s
Which of the following reactors has no back-mixing?
CSTR
Batch
PFR
Packed bed
The temperature dependency of reaction rate is best described by:
Arrhenius equation
Van’t Hoff equation
Ideal gas law
Le Chatelier's principle
A first-order reaction has a half-life of 10 minutes. What will be the concentration after 20 minutes if the initial concentration was 0.8 mol/L?
0.6
0.4
0.2
0.1
Which reactor is most suitable for large-scale gas-phase reactions?
Batch
CSTR
PFR
Tubular reactor
For an exothermic reaction, increasing temperature generally leads to:
Increase in rate
Decrease in rate
No change
Decrease in enthalpy
What happens to the rate of a zero-order reaction if the concentration is doubled?
Doubled
Tripled
Remains constant
Halved
A catalyst increases the reaction rate by:
Increasing activation energy
Lowering activation energy
Raising temperature
Increasing pressure
Le Chatelier’s principle is useful in:
Batch reactor design
Equilibrium reactions
Gas-solid reactions
Enzyme kinetics
The rate law r = k[A][B] suggests a:
First order
Zero order
Second order overall
Third order overall
The effectiveness factor in heterogeneous catalysis refers to:
Product formation
External diffusion
Internal diffusion limitations
Activation energy
What is the dimension of the rate constant (k) for a zero-order reaction?
mol/L·s
L/mol·s
1/s
L²/mol²·s
Which reactor type gives the highest conversion for a given volume?
Batch
CSTR
PFR
Fluidized bed
Which equation relates pressure, volume, temperature, and number of moles?
Arrhenius
Rate Law
Ideal Gas Law
Le Chatelier
The Damköhler number is the ratio of:
Diffusion to reaction rate
Flow rate to volume
Reaction rate to transport rate
Volume to conversion
For a first-order reaction in a batch reactor, pa lot of ln[A] vs. t gives:
Parabola
Straight line
Exponential curve
Constant line
The transfer function of a first-order lag system is given by:
Kp/s
Kp/s^2
Kp
Kp/(τp s + 1)
The dynamic behavior of a purely capacitive system is characterized by:
Adjusting itself to reach a new steady state
Unbounded process output growth with time
A constant output value at steady state
It poses no control problems
The dynamic behavior of a first-order system with a large time constant is characterized by:
A fast response
A slow response
Unbounded process output growth with time
A static gain of zero
The transfer function of a process with a single output is typically represented as:
A ratio of two polynomials
A differential equation
A linear equation
A quadratic equation
The poles of a transfer function are the:
Zeros of the numerator polynomial
Roots of the output equation
Zeros of the denominator polynomial
Roots of the input equation
The result of the system's response for a positive real distinct pole in a system's transfer function is:
Exponential decay
No effect on the system's response
Oscillatory behavior
Exponential growth
For a transfer function with complex conjugate poles, p1 = α+jβ and p1* = α-jβ which one of the following choices is true?
When α >0, the response of the system grows to infinity with decreasing amplitude
When α <0, the response of the system decays to zero with increasing amplitude
When α >0, the response of the system decays to zero with decreasing amplitude
When α <0, the response of the system decays to zero with decreasing amplitude
For a process with four inputs (disturbances and manipulated variables) and three measured outputs, how many transfer functions should you formulate? What is the corresponding transfer function matrix (order of matrix)?
4 transfer functions; Transfer function matrix order is 4x3
12 transfer functions; Transfer function matrix order is 3x4
7 transfer functions; Transfer function matrix order is 3x3
12 transfer functions; Transfer function matrix order is 4x4
During degree of freedom analysis for a distillation column with “N” number of trays (stages), how many variables of liquid and vapor compositions (separately) can we have?
N +1 liquid compositions and N vapor compositions
N+2 liquid compositions and N+1 vapor compositions
N liquid compositions and N vapor compositions
N liquid compositions and N+1 vapor compositions
In the context of control system design, what is the purpose of selecting measurement(s)?
To determine the control objective
To indirectly influence the unmeasured variable
To compare with the set point values
To select the manipulated variable
Which type of control configuration uses direct measurement of disturbances?
Feedback control
Feedforward control
Proportional control
Inferential control
What is the role of a controller in a control system?
To measure variables
To adjust manipulated variables
To select the control configuration
To define the control objective
When sugar is added to a coffee cup, the diffusion of sugar molecules into the solution is
Thermal transfer
Molecular mass transfer
Convective mass transfer
Mechanical mixing
Which of the following factors does NOT influence the rate of mass transfer?
Temperature
Concentration gradient
Color of the solution
Surface area
What is the primary difference between mass fraction and mass concentration?
Mass fraction is dimensionless, while mass concentration has units.
Mass fraction refers to the volume of a substance.
Mass concentration is always greater than mass fraction.
There is no difference; they are the same.
How does pressure affect the molecular diffusivity of gases?
Increases diffusivity with higher pressure
Decreases diffusivity with higher pressure
No effect on diffusivity
Only affects diffusivity at low temperatures
What is the main difference between adsorption and absorption?
Adsorption involves penetration into the material; absorption does not.
Adsorption occurs at the surface; absorption involves the entire volume.
Adsorption is a gas phase process; absorption is a liquid phase process.
Adsorption is reversible; absorption is not.
What happens to ion exchange cycles at high contaminant concentrations?
They become more efficient
They remain unchanged
They become shorter
They eliminate the need for regeneration
Which one of the following shows solid-to-gas mass transfer?
Burning of firewood
Rain formation
Brewing tea from a teabag
Diffusion of oxygen from the lungs to the blood
In solvent extraction, the residual feed solution containing little solute is called:
Raffinate
Extract
Solvent
Concentrate
Which property indicates that a liquid is more volatile?
Low vapor pressure
High boiling point
High vapor pressure
Low molecular weight
For substances with similar boiling points, their relative volatility is:
Greater than one
Less than one
Close to one
Unrelated to boiling points
Which equipment is primarily used in liquid-liquid extraction processes?
Packed column
Centrifuge
Cooling tower
Rotary dryer
In a differential manometer, a head of 0.6 m of fluid A in limb 1 is found to balance a head of 0.3 m of fluid B in limb 2. The ratio of specific gravities of A to B is;
2
0.5
Cannot be determined
0.18
Fluids with constant viscosity are categorized under
Non-Newtonian fluids
Incompressible fluids
Compressible fluids
Newtonian fluids
What is hydrostatic pressure?
Pressure exerted by a moving fluid
Pressure exerted by a fluid at rest
Pressure exerted by a gas
Pressure exerted by a solid object
The property of a fluid that determines its resistance to flow is called:
Viscosity
Density
Pressure
Surface tension
The viscosity of gases generally increases with:
Increasing temperature
Decreasing temperature
Increasing pressure
Decreasing pressure
Which one of the following statements is False?
The pressure in a fluid at rest increases with depth
In a fluid at rest, the pressure at a point remains constant
The pressure over a free surface of a fluid at rest will vary with location
On a free surface of a liquid, the pressure is the same at all points
Fluids with constant density are categorized under
Non-Newtonian fluids
Incompressible fluids
Compressible fluids
Newtonian fluids
The branch of fluid mechanics that deals with the motion of fluids without considering the forces causing the motion is called:
Fluid dynamics
Fluid kinematics
Fluid mechanics
Fluid statics
The branch of fluid mechanics that deals with the motion of fluids without considering the forces causing the motion is called:
Fluid dynamics
Fluid kinematics
Fluid mechanics
Fluid statics
The Navier-Stokes equation (Equation of motion) describes the:
Conservation of mass in fluid flow
Conservation of momentum in fluid flow
Conservation of energy in fluid flow
Conservation of density in fluid flow
In inviscid flow, which of the following statements is true?
Viscous forces dominate over inertial forces.
Viscous forces dominate over pressure forces
Inertial forces dominate over viscous forces.
Pressure forces dominate over inertial forces.
The continuity equation is the result of the application of the following law to the flow field
First law of thermodynamics
Newton's second law of motion
Conservation of energy
Conservation of mass
Which one of the following statements is false?
An ideal fluid has zero viscosity
Flow of gases is compressible flow
Pressure drop due to friction appears in reversible flow
Irreversibility in flow is due to friction effect
Streamlines in fluid flow represent:
The path lines of fluid particles
The velocity distribution within the fluid
The pressure distribution within the fluid
The energy distribution within the fluid
The Eulerian approach in fluid kinematics:
Follows the motion of individual fluid particles
Describes fluid flow using a fixed control volume
Considers the fluid flow in a Lagrangian reference frame
Considers the fluid flow in an arbitrary reference frame
The phenomenon of fluid flow where the fluid particles move in parallel layers with minimal mixing is called:
Compressible flow
Laminar flow
Turbulent flow
Incompressible flow
The stream function is used to describe:
Compressible flow
Irrotational flow
Turbulent flow
Laminar flow
The shape of the forced vortex under gravitational conditions is
Hyperboloid
spherical
parabolic
cylindrical
What does sphericity represent in the context of particles?
The degree of circularity of a particle
The roughness of the particle surface
The density of the particle
The size of the particle
Which mechanical unit operation is used to separate a liquid from a solid by passing the mixture through a porous medium?
Filtration
Sedimentation
Extraction
Distillation
Which of the following is not a mechanical unit operation?
Filtration
Distillation
Mixing
Crystallization
The power consumed in a size reduction process is directly proportional to the:
Feed rate
Particle size
Work index
Square of the speed of rotation
Which of the following characteristics is desirable for a filter medium in filtration?
High permeability
Low permeability
High porosity
Low porosity
The resistance offered by the filter medium to the flow of liquid is mainly due to:
Frictional forces between the liquid and the filter medium
Interactions between the liquid and the filter medium material
Interactions between the liquid and the particles in the cake
Frictional forces between the liquid and the particles in the cake
Assuming kicks law, if the work required for a crusher to reduce a feed of 800 mm size to a product of 80 mm size is 12 kJ. What would be the work required to reduce a feed of 100 cm size to a product of 100 mm size?
6 kJ
12 kJ
24 kJ
144 kJ
The process of transforming finely divided particles into particles of a larger size is
Size reduction
Crystallization
Centrifugation
Agglomeration
“All processes in nature tend to occur with an increase in entropy and the direction of change always leads to the increase in entropy”. This statement belongs to______________________.
Zeroth law
First law
Second law
Third law
A thermodynamic quantity which represents the total heat content of a system is called______.
Entropy
Temperature
Enthalpy
Pressure
Which one of the following is odd about Quasi-Static process?
It occurs infinite slowly
Every of its step in the system tends to remain in equilibrium
It is a reversible process
It is an irreversible process
Which of the following occurs without a change in the internal energy?
Isochoric process
Steady-state process
Isenthalpic process
Isentropic process
What is the value of the absolute thermodynamic temperature scale?
3k
0k
1k
4k
Which of the following follows the Carnot theorem?
Heat engines
Gas turbines engine
Gas compressors
All of the mentioned
Which of the following causes irreversibility?
Electrical resistance
In elasticity
Friction
All
Which of the following is known as the inequality of Clausius?
Cyclic integral of dW/T<=0
Cyclic integral of dW/T>=0
Cyclic integral of dQ/T>=0
Cyclic integral of dQ/T<=0
Choose the correct pair of properties that describe entropy?
Point function, intensive property
Point function, extensive property
Path function, extensive property
Path function, intensive property
The entropy of an isolated system can never __________________________.
Decrease
Increase
Be zero
None
Choose the correct statement from the given alternatives?
Q for reversible process < Q for irreversible process and work for reversible < work for irreversible
Q for reversible > Q for irreversible and work for reversible < work for irreversible
Q for reversible < Q for irreversible and work for reversible > work for irreversible
Q for reversible > Q for irreversible and work for reversible > work for irreversible
A pure substance which exists in a single phase has ____________ independent properties?
Zero
Two
One
Three
Which of the following is not a Maxwell equation?
(∂T/∂V) = -(∂P/∂S)
(∂P/∂T) = (∂S/∂V)
(∂T/∂P) = -(∂V/∂S)
(∂V/∂T) = -(∂S/∂P)
For an ideal gas, ____________________________________.
Volume expansivity = T and Joule-kelvin coefficient = 0
Volume expansivity = (1/T) and Joule-kelvin coefficient = 1
Volume expansivity = (1/T) and Joule-kelvin coefficient = 0
Volume expansivity = T and Joule-kelvin coefficient = 1
When does a vapor become a superheated?
When the temperature of vapour is less than the saturation temperature at given pressure
When the temperature of vapour is more than the saturation temperature at given pressure
When the temperature of vapour is equal to the saturation temperature at given pressure
None of the mentioned
Which of the following statements regarding ideal solutions is false?
Ideal solutions obey Raoult’s law under all conditions of temperature and concentrations
There will be some change in volume on mixing the components, i.e, ∆Vmixing ≠ 0
There will be no change in enthalpy when the two components are mixed, i.e., ∆V mixing ≠ 0
There will be no change in volume on mixing the components, i.e., Vmixing =0
Which one of the following thermodynamic quantities is not a state function?
Gibbs free energy
Enthalpy
Entropy
Work
What is the heat of reaction for 𝑪𝟔𝑯𝟔 + 𝟑𝑯𝟐 → 𝑪𝟔𝑯𝟏𝟐, if heat of formation of 𝑪𝟔𝑯𝟔, 𝑯𝟐 𝒂𝒏𝒅 𝑪𝟔𝑯𝟏𝟐
are 25J, 5J, and 50J respectively?
10J
30J
20J
35J
Which of the following statements will always apply when a reversible chemical reaction has attained equilibrium?
All reactants will convert to products
The reaction proceeds alternatively in the forward and reverse directions
The Gibbs free energy of the system reaches a minimum
The forward reaction will dominate over the reverse reaction
Which one of the following is an expression of the Van’t Hoff equation?
lnk = -∆H°/RT + ∆S°/R
∆H(T2) = ∆H(T1) + ∆Cp(T2-T1)
∆G°=∆H°-T∆S°
∆U=q+w
Which one the following is not correct about the reaction quotient (Qc) and the equilibrium constant (Kc)?
If Qc > Kc the system proceeds from right to left to reach equilibrium
If Qc = Kc the system is at equilibrium
If Qc < Kc the system proceeds from left to right to reach equilibrium
If Qc >Kc the system proceeds from right to left to reach equilibrium
______________ states that the rate of a reaction is directly proportional to concentration of reactants raised to their respective moles
Law of mass action
Kick’s law
Raoult’s law
Law of chemical equilibrium
The more effective way of increasing efficiency of Carnot engine is to ______.
Increase higher temperature
Decrease higher temperature
Increase lower temperature
Decrease lower temperature
What is the primary purpose of process control in process industries?
To improve employee efficiency
To reduce raw material usage to zero
To monitor and regulate process variables for consistent product quality
To automate office tasks
What is the main purpose of malting in beer production?
To increase alcohol content
To clarify the beer
To add carbonation
To convert starch into fermentable sugars
What is the main function of yeast during fermentation?
To clarify the beer
To consume sugars and produce alcohol
To add flavor
To remove proteins
What is the significance of the wort boiling process in brewing?
To cool the wort
To sterilize the wort and add hops
To clarify the beer
To ferment the sugars
What must be ensured during the beer filtration process for commercial shelf life?
The beer must be carbonated
The beer must be flavored
The beer must be rendered stable
The beer must be bottled
What is the purpose of soaking harvested grain in water during the malting process?
To dry the grain
To activate enzymes
To remove impurities
To enhance flavor
The main ingredient responsible for bitterness and aroma in beer is:
Malt
Hops
Yeast
Water
Which of the following is the main chemical reaction in the clinker formation stage of cement production?
Dehydration
Calcination
Combustion
Hydration
The purpose of adding gypsum in cement production is:
To control setting time
To accelerate setting time
To improve color
To increase strength
What is the purpose of treating juice with lime during clarification?
To sweeten the juice
To coagulate and remove impurities
To evaporate the juice
To crystallize the sugar
What is the final step in the sugar refining process?
Centrifugation
Crystallization
Evaporation
Milling
Which of the following materials can be blended with clinker to reduce CO2 emissions?
Limestone
Fly ash
Sand
Clay
Which of the following is NOT a main raw material for cement?
Lime (CaO)
Silica (SiO2)
Alumina (Al2O3)
Copper (Cu)
What is the primary method used to crystallize sugar from juice?
Cooling
Evaporation and concentration
Filtration
Distillation
Which of the following is NOT a typical responsibility of a chemical engineer?
Process design
Equipment fabrication
Heat and mass transfer analysis
Process optimization
Which of the following is NOT a primary variable in process control?
Temperature
Pressure
Flow rate
Color
The term 'process flow diagram (PFD)' refers to:
A detailed schematic of plant piping and instrumentation
A simplified diagram showing the flow of materials and major equipment
A blueprint of electrical wiring
A marketing strategy chart
In chemical engineering, molar flow rate is defined as:
Mass flow per unit time
Volume flow per unit time
Number of moles passing through a section per unit time
Total volume of the reactor
The process of separating components based on differences in boiling points is called:
Filtration
Distillation
Absorption
Adsorption
The Reynolds number is used to predict:
Heat transfer rate
Flow regime (laminar or turbulent)
Chemical reaction rate
Viscosity of liquids
The study of fluid flow, heat transfer, and mass transfer in chemical engineering is primarily concerned with:
Transport phenomena
Thermodynamics
Reaction kinetics
Process control
Among the following unit operations, find the odd one
Condensation
Evaporation
Distillation
Adsorption
Which type of heat exchanger analysis method can be used to determine the heat
transfer rate and outlet temperatures of the hot and cold fluids for prescribed fluid
mass flow rates and inlet temperatures when the type and size of the heat exchanger
are specified?
LMTD method
ε -NTU method
Both
None
Which one of the following modes of heat transfer plays a major role in heat
transfer during the boiling and condensation process?
Conduction
Convection
Radiation
Conduction and Convection
In the case of a parallel flow heat exchanger, the lowest temperature theoretically
attainable by the hot fluid is
Equal to the outlet temperature of the cold fluid
More than the outlet temperature of the cold fluid
Less than the outlet temperature of the cold fluid
Either more or less than the outlet temperature of the cold fluid (depending upon the
fluid)
In a liquid-liquid heat exchanger, for the same process temperature, the ratio of
the LMTD in parallel flow to the LMTD in counter flow is always
<1
>1
1
Infinity
The Fourier number is used in the analysis of problems involving heat transfer by
Forced convection
Natural convection
Transient conduction
Steady state conduction
What is the common law for mass transfer that is analogous to Fourier’s law of
conduction in heat transfer?
Newton’s law of cooling
Taylor’s law
Fick's law
Dalton's law
In a convective mass transfer process, what dimensionless number is analogous to
the Nusselt number in heat transfer and relates convective mass transfer to diffusive
mass transfer?
Reynolds number
Sherwood number
Schmidt number
Lewis number
The rate of heat conduction through a thick sphere of radius r1 and r2 is equal to:
4𝜋𝑘(𝑇1-𝑇2)/(𝑟2-𝑟1)
4𝜋𝑘 𝑟1𝑟2/(𝑟2-𝑟1)
4𝜋𝑘 𝑟1𝑟2(𝑇1-𝑇2)/(r2-r1)
2𝜋𝑘𝐿(𝑇1-𝑇2)/ ln(𝑟2/𝑟1)
In the equation Q = UAΔT; where ΔT is
Geometric mean temperature difference
Arithmetic mean temperature difference
Logarithmic mean temperature difference
The difference in average bulk temperatures of hot and cold fluids
NPV (Net Present Value) is preferred over payback period because:
It is easier to calculate
It considers the time value of money
It always gives higher returns
It ignores future cash flows
Which of the following best defines IRR (Internal Rate of Return)?
The discount rate at which NPV = 0
The interest rate on a bank loan
The highest rate of project failure
The ratio of capital to operating cost
Which type of flow sheet includes the most detail?
Block flow diagram
Process flow diagram (PFD)
P&ID
Layout drawing
If operating costs increase but revenue remains the same, the break-even point:
Increases
Decreases
Stays constant
Drops to zero
The steady state temperature distribution in a wall is given by T = 300 - 3050x2, where x (in meters) is the position in the wall and T is the temperature (in oC). The thickness of the wall is 0.2 m, and the thermal conductivity of the wall is 1.2 (W/m oC). The wall dissipates the heat to the ambient at 30 °C. What is the heat transfer coefficient of the wall's surface at 0.2 m?
12.5W/m2oC
9.89W/m2oC
9.5W/m2oC
10.89W/m2oC
In a heat exchanger, it is observed that ΔT1 = ΔT2, where ΔT1 is the temperature
difference between the two single-phase fluid streams at one end and ΔT2 is the
temperature difference at the other end. This heat exchanger is
A condenser
A counterflow heat exchanger
An evaporator
A parallel flow heat exchanger
