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Interview MCQ Set 1

1. How is the separation of uranium isotopes carried out?
a) Centrifugation
b) Electrodialysis
c) Electrophoresis
d) Thermal diffusion

View Answer

Answer: a [Reason:] Centrifugation helps separation of isotopes based on molecular weights.

2. How is the separation of chlorine isotopes carried out?
a) Centrifugation
b) Electrodialysis
c) Electrophoresis
d) Thermal diffusion

View Answer

Answer: d [Reason:] Thermal diffusion helps in the separation of chlorine isotopes.

3. Which separation technique is used to concentrate heavy water?
a) Centrifugation
b) Electrodialysis
c) Electrolysis
d) Thermal diffusion

View Answer

Answer: c [Reason:] Electrolysis is the technique used to concentrate heavy water.

4. Which separation technique is used for desalinization of sea water?
a) Centrifugation
b) Electrodialysis
c) Electrophoresis
d) Thermal diffusion

View Answer

Answer: b [Reason:] Electrodialysis is used in desalinization of sea water.

5. How are hemicelluloses recovered?
a) Centrifugation
b) Electrophoresis
c) Electrolysis
d) Thermal diffusion

View Answer

Answer: b [Reason:] Electrophoresis is used in recovering of hemicelluloses.

6. What field is applied in fled-flow fractionation?
a) Thermal gradient
b) Centrifugal force field
c) Perpendicular electric or magnetic field
d) Parallel electric or magnetic field

View Answer

Answer: c [Reason:] A perpendicular electric or magnetic field is applied to the laminar flow.

7. What do the cation and anion permeable membrane do in electro-dialysis?
a) Disallows migration of species of same charge
b) Facilitates the migration of species of same charge
c) Separates the protons and electrons
d) Removes the ions

View Answer

Answer: a [Reason:] A cation or anion membrane carries a fixed charge that prevents the migration of species of same charge.

8. What happens when a temperature gradient is applied?
a) Components flow at different rates
b) Charged components migrate to opposite sides
c) The high melting component melts
d) Concentration gradient is formed

View Answer

Answer: d [Reason:] A concentration gradient is formed due to temperature that gives the separation using thermal diffusion.

9. What is the role of centrifugal force field?
a) Establishes a magnetic field
b) Establishes a pressure filed
c) Establishes an electric field
d) Settles down the heavier particles

View Answer

Answer: b [Reason:] The centrifugal filed establishes a pressure field that separates fluid mixtures according to molecular weights.

10. Why is an external field or gradient applied?
a) To increase the speed of separation
b) To start the separation
c) To decrease the byproducts
d) To obtain maximum efficiency

View Answer

Answer: b [Reason:] The external field is not employed to increase efficiency or speed but it is the driving force in the separation.

Interview MCQ Set 2

1. Which of the following is not an application of transport in membranes?
a) Microfiltration
b) Reverse osmosis
c) Dialysis
d) Fractional distillation

View Answer

Answer: d [Reason:] Fractional distillation is not an application of transport in membranes.

2. What cannot be a size of membrane?
a) Nano porous
b) Macroporous
c) Microporous
d) Non-porous

View Answer

Answer: a [Reason:] A membrane cannot be nano porus.

3. If the pressure drop(ΔP) is 1000 units, the flux(J) is 50 units,what is the hydraulic membrane permeability?
a) 0.02
b) 0.04
c) 0.05
d) 0.06

View Answer

Answer: c [Reason:] Since L= J/ΔP, L= 0.05 .

4. If the pressure drop(ΔP) is 1000 units, the flux(J) is 60 units,what is the hydraulic membrane permeability?
a) 0.02
b) 0.04
c) 0.05
d) 0.06

View Answer

Answer: d [Reason:] Since L= J/ΔP, L= 0.06 .

5. If the pressure drop(ΔP) is 1000 units, the flux(J) is 40 units,what is the hydraulic membrane permeability?
a) 0.02
b) 0.04
c) 0.05
d) 0.06

View Answer

Answer: b [Reason:] Since L= J/ΔP, L= 0.04 .

6. If the pressure drop(ΔP) is 500 units, the flux(J) is 50 units,what is the hydraulic membrane permeability?
a) 0.01
b) 0.04
c) 0.05
d) 0.06

View Answer

Answer: a [Reason:] Since L= J/ΔP, L= 0.01 .

7. If the pressure drop(ΔP) is 1000 units, the flux(J) is 50 units,what is the hydraulic membrane permeability?
a) 0.02
b) 0.04
c) 0.05
d) 0.06

View Answer

Answer: c [Reason:] Since L= J/ΔP, L= 0.05 .

8. If the pressure drop(ΔP) is 200 units, the flux(J) is 100 units,what is the hydraulic membrane permeability?
a) 0.02
b) 0.04
c) 0.5
d) 0.6

View Answer

Answer: c [Reason:] Since L= J/ΔP, L= 0.5 .

9. If the pressure drop(ΔP) is 1000 units, the flux(J) is 200 units,what is the hydraulic membrane permeability?
a) 0.2
b) 0.4
c) 0.5
d) 0.06

View Answer

Answer: a [Reason:] Since L= J/ΔP, L= 0.2 .

10. If the pressure drop(ΔP) is 1000 units, the flux(J) is 300 units,what is the hydraulic membrane permeability?
a) 0.67
b) 0.33
c) 0.54
d) 0.06

View Answer

Answer: b [Reason:] Since L= J/ΔP, L= 0.33 .

Interview MCQ Set 3

1. What is the semi-permeable membrane used in separation techniques made from?
a) Animal calls
b) Plant cells
c) Egg shells
d) Natural fibers

View Answer

Answer: d [Reason:] Natural fibers act best as semi-permeable membrane.

2. What is separation effected by in microporous membranes?
a) Difference in solubility
b) Rate of species diffusion through the pores
c) Amount of feed to the membranes
d) Number of membranes used

View Answer

Answer: b [Reason:] Rate of species diffusion through the pores.

3. What is separation effected by in non-porous membranes?
a) Differences In solubility in the membrane
b) Rate of species diffusion through the pores
c) Amount of feed to the membranes
d) Number of membranes used

View Answer

Answer: a [Reason:] The differences in solubility lead to the separation in case of non-porous membranes.

4. What is meant by osmosis?
a) A process where molecules of a solute travel from more concentrated solution to less concentrated solution
b) A process where molecules of solute travel from less concentrated solution to more concentrated solution
c) A process where molecules of solvent travel from less concentrated solution to more concentrated solution through a semi-permeable membrane
d) A process where molecules of solvent travel from more concentrated solution to less concentrated solution through a semi-permeable membrane

View Answer

Answer: c [Reason:] The solvent travels from less concentration to more concentration thus equalizing the ncentration.This process is called as osmosis.

5. Why do reverse osmosis occur?
a) Because the concentration is more in the other region
b) Because the semi-permeable membrane has a tendency
c) Because solute molecules start travelling from high concentration to low concentration
d) Because a reverse pressure greater than the osmotic pressure is applied

View Answer

Answer: d [Reason:] When a pressure greater than the osmotic pressure is applied in the reverse direction the solvent molecules reverses their path.

6. In which separation process is the heat of evaporation required?
a) Desublimation
b) Pervaporation
c) Crystallization
d) Reverse osmosis

View Answer

Answer: b [Reason:] The species transported through non porous membranes are evaporated and used.Thus there is a requirement of heat of evaporation.

7. Which of the following separation techniques DO NOT use a solid agent?
a) Adsorption
b) Ion-exchange
c) Chromatography
d) Stripping

View Answer

Answer: d [Reason:] There is no requirement of a solid agent in the process of separation by stripping.

8. Why is a solid adsorbent used in the separation technique of adsorption?
a) Because the components selectively adsorb and desorb from the solid surfaces
b) Because the transportation of solid adsorbents is easy
c) There are no known liquid adsorbents
d) Using a solid adsorbent lessens the heat of evaporation

View Answer

Answer: a [Reason:] Components move through the bed at different rates when the solid adsorbent is used.

9. Demineralization of water is done by which process?
a) Adsorption
b) Chromatography
c) Ion-Exchange
d) Distillation

View Answer

Answer: c [Reason:] Ion-exchange is used to remove salts and their corresponding charged metals to demineralize water.

10. What are the solid agents in form of?
a) Thick beds
b) Tubes
c) Flat sheets
d) Granular material

View Answer

Answer: d [Reason:] Solid agents are in forms of granular material that increase the exposed surface area.

Interview MCQ Set 4

1. What happens in a batch mode of contact filtration?
a) A batch of liquid is contacted with a batch of adsorbent for a period of time → followed by discharge of the slurry from the vessel, and filtration to separate solids from liquid
b) Liquid and adsorbent are continuously added to and removed from the agitated vessel
c) liquid is continuously fed, then removed from the vessel, where it is contacted with adsorbent, which is retained in a contacting zone of the vessel until it is nearly spent
d) Simultaneous continuous and batch mode operated

View Answer

Answer: a [Reason:] In the batch mode A batch of liquid is contacted with a batch of adsorbent for a period of time followed by discharge of the slurry from the vessel, and filtration to separate solids from liquid.

2. What happens in a batch mode of contact filtration?
a) A batch of liquid is contacted with a batch of adsorbent for a period of time followed by discharge of the slurry from the vessel, and filtration to separate solids from liquid
b) Liquid and adsorbent are continuously added to and removed from the agitated vessel
c) liquid is continuously fed, then removed from the vessel, where it is contacted with adsorbent, which is retained in a contacting zone of the vessel until it is nearly spent
d) Simultaneous continuous and batch mode operated

View Answer

Answer: b [Reason:] In the continuous mode Liquid and adsorbent are continuously added to and removed from the agitated vessel.

3. What happens in a batch mode of contact filtration?
a) A batch of liquid is contacted with a batch of adsorbent for a period of time followed by discharge of the slurry from the vessel, and filtration to separate solids from liquid
b) Liquid and adsorbent are continuously added to and removed from the agitated vessel
c) liquid is continuously fed, then removed from the vessel, where it is contacted with adsorbent, which is retained in a contacting zone of the vessel until it is nearly spent
d) Simultaneous continuous and batch mode operated

View Answer

Answer: c [Reason:] In the semi continuous mode liquid is continuously fed, then removed from the vessel, where it is contacted with adsorbent, which is retained in a contacting zone of the vessel until it is nearly spent.

4. Calculate the values of α is:
external liquid-phase mass-transfer coefficient k= 0.5
liquid volume Q= 100 litres
mass of adsorbentS = 5grams
a) 20
b) 40
c) 50
d) 60

View Answer

Answer: b [Reason:] Since α= Q/SK, α= 100/2.5=40.

5. Calculate the values of α is:
external liquid-phase mass-transfer coefficient k= 0.5
liquid volume Q= 100 litres
mass of adsorbentS = 10grams
a) 20
b) 40
c) 50
d) 60

View Answer

Answer: a [Reason:] Since α= Q/SK, α= 100/5=20.

6. a change in pressure has little or no effect on equilibrium loading for liquid adsorptionWhich of the following is untrue about pressure swing adsorption?
a) While one bed adsorbs, the other bed desorbs
b) Mechanical work is used to increase pressure
c) With valving, the cyclic sequence can be programmed to operate automatically
d) Applicable for only liquids

View Answer

Answer: d [Reason:] Applicable only for gases because a change in pressure has little or no effect on equilibrium loading for liquid adsorption.

7. Calculate the values of β is:
External liquid-phase mass-transfer coefficient k= 0.5
Liquid volume Q= 100 litres
Mass of adsorbent S = 8grams
a) 26
b) 48
c) 25
d) 60

View Answer

Answer: a [Reason:] Since β = 1+Q/SK, β =1+ 100/4=25.

8. Calculate the values of β is:
External liquid-phase mass-transfer coefficient k= 0.5
Liquid volume Q= 100 litres
Mass of adsorbent S = 10grams
a) 26
b) 48
c) 21
d) 60

View Answer

Answer: c [Reason:] Since β = 1+Q/SK, β =1+ 100/5=21.

9. Calculate the values of β is:
external liquid-phase mass-transfer coefficient k= 0.5
liquid volume Q= 100 litres
mass of adsorbentS = 16grams
a) 12.5
b) 13.5
c) 25
d) 27

View Answer

Answer: b [Reason:] Since β = 1+Q/SK, β =1+ 100/8=13.5.

10. Calculate the values of β is:
External liquid-phase mass-transfer coefficient k= 0.5
Liquid volume Q= 100 litres
Mass of adsorbent S = 6grams
a) 33.33
b) 35.33
c) 66.66
d) 34.33

View Answer

Answer: d [Reason:] Since β = 1+Q/SK, β =1+ 100/3=34.33.

Interview MCQ Set 5

1. A material balance for any soluble material B around any interior stage from n=2 to N-1 is:
a) Y n+1 S + X n-1 RF A =Y n S + X n RF A
b) Y n+1 S + X n-2 RF A =Y n S + X n RF A
c) Y n+1 S + X n+1 RF A =Y n S + X n RF A
d) Y n+1 + X n-2 RF A =Y n S + X n RF A

View Answer

Answer: a [Reason:] Material balance for any soluble material B around any interior stage from n=2 to Y n+1 S + X n-1 RF A =Y n S + X n RF A Where Y j is the mass of solute per mass of solvent and F A is the mass flow rate of slurry and R is the constant ratio of mass of solvent to mass of insoluble solids.

2. Which equation holds true at equilibrium?
a) Y N+1 = Y N
b) X N = Y N
c) F B = F A
d) R 1 =R 2

View Answer

Answer: b [Reason:] At equilibrium the concentration of B in each overflow equals the concentration of B in liquid part.

3. What is the formula for washing factor?
a) W= SRF A
b) W= RF A /S
c) W=SF A/R
d) W=S/RF A

View Answer

Answer: d [Reason:] The formula for washing factor is W=S/RF A, where F A is the mass flow rate of slurry and R is the constant ratio of mass of solvent to mass of insoluble solids.

4. The concentration of solute is given by:
a) (F B /S)(1/W Nsub>n-1 )
b) (F B S)(1/W sub>n-1 )
c) (F B /S)(1/W sub>n-1 )
d) (F B S)(W sub>n-1 )

View Answer

Answer: c [Reason:] The concentration of solute X N is given by (F B /S)(1/W sub>n-1 ) where S is the flow rate at stage N and F B is the mass flow rate of slurry and W is the washing factor.

5. What will be the concentration of solute in overflow doe N=2?
a) (F B /S)(1/W +1)
b) (F B /S)(1+W+W 2 /W 2 )
c) (F B /S)(1+W+W 2 /W)
d) (F B /S)(1+W/W 2 )

View Answer

Answer: a [Reason:] (F B /S)(1/W +1) is the equation used. Now for N=2, (F B /S)(1/W +1)= (F B /S)(1/W +1).

6. Which of the following is true about cascades for a particular S?
a) Maximizes Y 1
b) Maximizes X N
c) Minimizes Y 1
d) Does not affect X N

View Answer

Answer: a [Reason:] The cascade for any given S, maximizes Y 1 , the amount of B dissolved in a solvent nleaving stage 1.

7. The minimum amount of solvent required is underflow ratio is 0.5 and insoluble solids feed rate is 2000Kg/hr is:
a) 2000kg/hr
b) 1000kg/hr
c) 4000kg/hr
d) 500kg/hr

View Answer

Answer: b [Reason:] S min =RF A , thus S min = 2ooo*0.5=1oookg/hr.

8. What is the washing factor if solvent feed rate is 3000kh/hr , underflow ratio is 0.5 and insoluble solids feed rate is 2000?
a) 2
b) 3
c) 4
d) 5

View Answer

Answer: b [Reason:] Since W= S/RFA , W= 3000/2000*0.5=3.

9. The minimum amount of solvent required is underflow ratio is 0.3 and insoluble solids feed rate is 200Kg/hr is:
a) 50kg/hr
b) 600kg/hr
c) 666.66kg/hr
d) 60kg/hr

View Answer

Answer: d [Reason:] S min =RF A , thus S min = 2oo*0.3=600kg/hr.

10. What is the washing factor if solvent feed rate is 2500kh/hr , underflow ratio is 0.3 and insoluble solids feed rate is 500?
a) 13.33
b) 166.66
c) 16.66
d) 133.33

View Answer

Answer: c [Reason:] Since W= S/RFA , W= 2500/500*0.3=16.66.

11. What is the washing factor if solvent feed rate is 2500kh/hr , underflow ratio is 0.5 and insoluble solids feed rate is 2000?
a) 0.5
b) 1
c) 1.5
d) 2.5

View Answer

Answer: d [Reason:] Since W= S/RFA , W= 2500/1000*0.5=2.5.

12. What is the washing factor if solvent feed rate is 2800kh/hr , underflow ratio is 0.7 and insoluble solids feed rate is 2000?
a) 1
b) 2
c) 3
d) 4

View Answer

Answer: b [Reason:] Since W= S/RFA , W= 2800/2000*0.7=2.

13. What is the washing factor if solvent feed rate is 3000kh/hr , underflow ratio is 0.2 and insoluble solids feed rate is 10000?
a) 1
b) 2.5
c) 1.5
d) 4

View Answer

Answer:c [Reason:] Since W= S/RFA , W= 3000/10000*0.2=1.5.

14. What is the washing factor if solvent feed rate is 1000kh/hr , underflow ratio is 0.1 and insoluble solids feed rate is 10000?
a) 1
b) 2
c) 3
d) 4

View Answer

Answer: a [Reason:] Since W= S/RFA , W= 1000/10000*0.1=1.

15. What is the washing factor if solvent feed rate is 2300kh/hr , underflow ratio is 0.3 and insoluble solids feed rate is 2000?
a) 1.97
b) 2.33
c) 3.07
d) 3.83

View Answer

Answer: c [Reason:] Since W= S/RFA , W= 2300/2000*0.3=3.83.