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Multiple choice question for engineering

Set 1

1. When is the copolymerization said to be an ideal copolymerization?
a) Copolymer composition F1 not equal to monomer feed composition f1
b) r1r2=1
c) r1=r2
d) r1=1

View Answer

Answer: b [Reason:] A copolymerization is said to be an ideal copolymerization when the chain radicals have equal preference to add one of the monomers over the other.

2. Which of the following is true if the two monomers involved in copolymerization, are equally reactive with each radical?
a) r1=r2=1
b) F1=f1
c) random arrangement of monomer units
d) all of the mentioned

View Answer

Answer: d [Reason:] When r1=r2=1, then under such condition, the monomers are equally reactive with chain radicals and the radicals cannot distinguish between the two monomers. Moreover, the composition of copolymer is the same as that in the feed and the monomer units are arranged in a random manner.

3. As the difference in the reactivities of the both significant monomers increases, an increasing difficulty in the production of copolymer is encountered as a result of ideal copolymerization. State true or false.
a) True
b) False

View Answer

Answer: a [Reason:] In case of r1>1 and r2<1 and vice versa, one of the monomer is more reactive than the other towards the propagating species resulting into the higher proportion of more reactive monomer unit in the copolymer formed. With larger differences in reactivities, the formation of copolymer becomes difficult as the more reactive monomer will undergo fast depletion from the monomer mixture.

4. Which of the following is correct regarding the alternate copolymerization?
a) r1r2=1
b) r1=r2=1
c) r1r2=0
d) r1r2>1

View Answer

Answer: c [Reason:] For perfect alternation in the copolymer structure the values of r1 and r2 are nearly equal to zero, as the chain growth strictly takes place by cross-propagation.

5. What is the value of copolymer composition (mole fraction), F1 for alternate copolymerization?
a) 0.5
b) 1
c) r1
d) 2

View Answer

Answer: a [Reason:] For alternation, r1=r2=0 And F1 = (r1f12+f1f2)/(r1f12+2f1f2+r2f22) Substituting the values, we obtain F1= 0.

6. Which of the following combinations undergoing polymerization give polysulphones?
a) olefins and sulphur dioxide
b) cycloolefins and metal sulphate
c) olefins and sulphur trioxide
d) vinyl monomer and sulphur ring

View Answer

Answer: a [Reason:] Polysuplhones are obtained by the radical polymerization of monomers like olefins, cyclo-olefins, vinyl compounds in liquid sulphur dioxide.

7. Calculate the feed composition for azeotropic copolymerization of methy methacrylate and styrene at 60ᵒC.(Given that r1=0.46 and r2=0.52)
a) 0.47
b) 0.56
c) 0.235
d) 0.94

View Answer

Answer: a [Reason:] For azeotropic copolymerization, (f1)c = (1-r2)/(2-r1-r2) Substituting the values, we get (f1)c = 0.47.

8. What is the composition of copolymer formed by the copolymerization of 60% vinyl acetate and 40% vinyl chloride at 60ᵒC, given that r1=0.23 and r2=1.68?
a) 0.39
b) 0.78
c) 0.63
d) cannot be determined

View Answer

Answer: a [Reason:] The copolymer composition is calculated by the following equation- F1 = (r1f12+f1f2)/(r1f12+2f1f2+r2f22) Substituting the values, we obtain F1= 0.39.

9. What is the copolymer composition for azeotropic copolymerization of Acrylonitrile and 1,3-butadiene at 50ᵒC, given that r1=0.02 and r2=0.30?
a) 0.21
b) 0.417
c) 0.84
d) 0.62

View Answer

Answer: b [Reason:] For azeotropic copolymerization, Critical feed monomer composition is given by-(f1)c=(1-r2)/(2-r1-r2) Substituting the values, we get (f1)c=0.42 And copolymer composition is given by- F1 = (r1f12+f1f2)/(r1f12+2f1f2+r2f22). Thus, F1= 0.417.

10. Methacrylic acid and 2-vinyl pyridine are copolymerized together at 70ᵒC, where r1 and r2 have values 0.58 and 1.55, respectively. Which of the following component is present in more quantity in the copolymer formed in earlier stage?
a) methacrylic acid
b) 2-vinyl pyridine
c) equimolar composition
d) none of the mentioned

View Answer

Answer: b [Reason:] For the reaction of copolymerization, k1,1=0.58k1,2 and k2,2=1.55k2,1. In both the cases, 2-vinyl pyridine is consumed at a faster rate than methacrylate by each of the radicals. So 2-vinyl pyridine is present in more quantity in the copolymer formed at an earlier stage.

11. Which of the following polymerization proceeds without the change in the composition of feed as well as copolymer?
a) block polymerization
b) ideal polymerization
c) azeotropic polymerization
d) alternate polymerization

View Answer

Answer: c [Reason:] When the polymerization proceeds without a change in feed and copolymer composition, then there is an occurrence of azeotropic polymerization.

Set 2

1. Cellulose viscosity of mechanical pulps and of high yield pulps are not measured since it’s quite low .
a) True
b) False

View Answer

Answer: b [Reason:] Cellulose viscosity of mechanical pulps and of high yield pulps are not measured since it’s quite high and not a factor in the strength properties of papers derived from these pulps.

2. Mechanical pulp bleaching is accomplished with various compounds containing Cl or O2 and alkali extractions in several stages.
a) True
b) False

View Answer

Answer: b [Reason:] Chemical pulp bleaching is accomplished with various compounds containing Cl or O2 and alkali extractions in several stages.

3. 2NaCl + 2 H2O + ____________ andrarr; Cl2 + 2NaOH + H2
a) Electricity
b) Heat
c) Acid
d) Alkali

View Answer

Answer: a [Reason:] Chlorine is not overly specific to lignin, and much carbohydrate degradation occurs through its use.

4. The ____________ stage is a modification of C stage bleaching, where some of the chlorine is replaced with ClO2.
a) AD
b) CD
c) FD
d) MD

View Answer

Answer: b [Reason:] The CD stage is a modification of C stage bleaching, where some of the chlorine is replaced with ClO2.

5. The ____________ is the process of extraction of degraded lignin compounds, which could increment the chemical usage in subsequent bleaching stages.
a) A stage
b) B stage
c) C stage
d) E stage

View Answer

Answer: d [Reason:] The E stage’s Extraction of de-graded lignin compounds, which could increment the chemical usage in subsequent bleaching stages.

6. Lignin-Cl + NaOH and rarr;Lignin-OH + NaCl
The lignin in the E effluent gives a ____________ colour that’s ultimately responsible for much of the colour of the final mill effluent.
a) Light
b) Dark
c) Transparent
d) Full black

View Answer

Answer: b [Reason:] The lignin in the E effluent gives a dark colour that is ultimately responsible for much of the colour of the final mill effluent.

7. ____________ and other chemicals are considered for bleaching stages, but don’t enjoy commercial importance.
a) Nitrogen oxides
b) Nitrogen peroxide
c) Nitrous hydroxide
d) Hydrogen

View Answer

Answer: a [Reason:] NO2 and other chemicals are considered for bleaching stages, but don’t enjoy commercial importance.

8. ____________ is a term used to describe each of 2 completely different methods. 1st is the utiliztion of enzymes which are isolated from decay fungi to selectively de-grade lignin.
a) Bio electric
b) Bio bleaching
c) Electrocuting
d) Bio degredation

View Answer

Answer: b [Reason:] Bio bleaching is a term used to describe each of 2 completely different methods. It’s akin to biopulping, and, like biopulping, is still only in the laboratory stages.

9. Bleaching with H2O2, is not common for chemical pulps. (But this is changing somewhat as mills look for chlorine-free systems.) It’s used for brightening mechanical pulps. What is the name of the alternative method utilized?
a) E stage
b) H stage
c) P stage
d) D stage

View Answer

Answer: c [Reason:] It’s utilized for brightening mechanical pulps, but when it’s used to bleach chemical pulps it appears as the last stage of a sequence such as C-E-H-P or C-E-H-D-P.

10. The ____________ is extraction of de-graded lignin compounds, which would increment the chemical usage in subsequent bleaching stages.
a) B stage
b) C stage
c) D stage
d) E stage

View Answer

Answer: d [Reason:] The E stag’s extraction of de-graded lignin compounds, which would increment the chemical usage.

Set 3

1. The value of mineral residue left after the complete combustion of organic material represents the latex.
a) True
b) False

View Answer

Answer: b [Reason:] The value of mineral residue left after the complete combustion of organic material represents the ash content.

2. Ash content is a measure of filler content in papers containing clay, and CaCO3.
a) True
b) False

View Answer

Answer: a [Reason:] Ash content’s a measure of filler content in papers containing clay, CaCO3, or TiO2 fillers and soda content in brown papers.

3. _________ with energy dispersive x-ray analysis (E.D.A.X.) is a very useful tool for qualitative and semi-quantitative analysis of elements.
a) Scattering electron microscopy
b) Scattering ion microscopy
c) Scanning electron microscopy
d) Scanning ion microscopy

View Answer

Answer: c [Reason:] Scanning electron microscopy (S.E.M.) with energy dispersive x-ray analysis (E.D.A.X.) is a very important tool for qualitative and semi-quantitative analysis of elements with atomic no. of 13 or higher aluminium on the surface of paper.

4. _________ is very important for looking at element distributions upon the surface or through the thickness of paper if cross-sections are made.
a) Scattering electron microscopy
b) Scattering ion microscopy
c) Scanning electron microscopy
d) Scanning ion microscopy

View Answer

Answer: c [Reason:] Selecting electron microscopy(S.E.M.) is very useful for looking at element distributions on the surface or through the thickness of paper if cross-sections are made.

5. Elements are bombarded with electron and they give off X-rays at frequencies which are measured in energy units of electron volts. What is the name of the process?
a) Scanning ion microscopy
b) Scattering ion microscopy
c) Scattering electron microscopy
d) Scanning electron microscopy

View Answer

Answer: d [Reason:] Elements are bombarded with electron and they release X-rays at frequencies which are measured in energy units of electron volts. With proper calibration, the no. of X-ray’s released show the relative amount of that material.

6. The determination of Na, Ca, Cu, Fe, and Mg content of pulp and paper is done by _________
a) Atomic absorption microscopy
b) Electronic absorption microscopy
c) Ionic absorption microscopy
d) Electronic adsorption microscopy

View Answer

Answer: b [Reason:] The determination of Na, Ca, Cu, Fe, and Mg content of pulp and paper by atomic absorption spectroscopy.

7. The adhesive on top of the coating does not alter the spectrum except to attenuate the signal, since the adhesive contains only light elements. The coated sheet contains these elements in addition to _________
a) Zinc and chloride
b) Zinc and hydrochloride
c) Zinc silicate and hydrochloride
d) Magnesium and chloride

View Answer

Answer: a [Reason:] The coated sheet contains these elements in addition to Zn and Cl (possibly from a zinc oxide filler.) The adhesive on top of the coating does not alter the spectrum except to attenuate the signal, since the adhesive contains only light elements and absorbs some of the electrons before they can reach other elements beneath them.

8. _________ method has numerous important widespread applications to scale residues, corrosion products, and sludge analysis. The method is simple, fast, and reliable.

a) Scattering electron microscopy
b) Scattering ion microscopy
c) Scanning electron microscopy
d) Scanning ion microscopy

View Answer

Answer: c [Reason:] Scanning electron microscopy method has numerous important widespread applications to scale residues, corrosion products, and sludge analysis. The method is simple, fast, and reliable.

9. The use of various types of _________ is becoming increasingly important in paper in order to increase its strength and to increase the retention of fines, fillers, and other materials.
a) Lignin
b) Pulpwood
c) Starch
d) Gum

View Answer

Answer: c [Reason:] The use of various types of starch is becoming increasingly important in paper in order to increase its strength and to increase the retention of fines, fillers, and other materials. In the latter case, cationic starches are commonly used.

10. _________ may be measured qualitatively by an iodine solution or quantitatively by HCl extraction followed by colorimetric determination with iodine.
a) Lignin
b) Pulpwood
c) Starch
d) Gum

View Answer

Answer: c [Reason:] Starch may be measured qualitatively by an iodine solution or quantitatively by HCl extraction followed by colorimetric determination with iodine.

Set 4

1. What is the name of the process of breaking down the chemical structure of lignin and rendering it soluble in a liquid?
a) Delignification
b) Dissolving pulp
c) Cross recovery
d) Kraft green liquor semi-chemical process

View Answer

Answer: a [Reason:] Delignification is the name of the process of breaking down the chemical structure of lignin and rendering it soluble in a liquid. The liquid is water, except for organosolv pulping.

2. What is the correct definition of Kappa number?
a) It is the measure of the protein content of pulp
b) It is the measure of the lignin content of pulp
c) It is the measure of the minerals content of pulp
d) It is the measure of the bleaching content of pulp

View Answer

Answer: b [Reason:] It’s the measure of the lignin content of pulp. The more the Kappa number more the Lignin content.

3. What is the other name of permanganate number?
a) L number
b) K number
c) M number
d) C number

View Answer

Answer: b [Reason:] The number is used to monitor the amount of delignification of chemical pulps after pulping process and in between bleaching stages.

4. The pulp viscosity is a measure of the average chain length of cellulose.
a) True
b) False

View Answer

Answer: a [Reason:] The pulp viscosity is a measure of the average chain length of cellulose. It’s determined after dissolving the pulp in a suitable solution such as cupriethylenediamine solution.

5. What is the name of the hidden black region?
pulp-paper-questions-answers-general-chemical-pulping-q5
a) Pre-streaming Chamber
b) Post-streaming chamber
c) Residue-streaming chamber
d) Slurry-streaming chamber

View Answer

Answer: a [Reason:] The Kamyr continuous digester.

6. What is the name of the question mark region?
pulp-paper-questions-answers-general-chemical-pulping-q6
a) Screw feeder
b) Rotary feeder
c) Blow line
d) Discharger

View Answer

Answer: c [Reason:] Blow tank’s vessel is used to receive pulp discharged from a digester and to reduce the pressure level to atmospheric.

7. What is the name of the question mark region?
pulp-paper-questions-answers-general-chemical-pulping-q7
a) Screw feeder
b) Stock line
c) Vent
d) Digester

View Answer

Answer: c [Reason:] Blow tank’s a vessel used to receive pulp discharged from a digester and to reduce the pressure level to atmospheric.

8. What is the name of the question mark region?
pulp-paper-questions-answers-general-chemical-pulping-q8
a) Screw feeder
b) Stock line
c) Rotary feeder
d) Digester

View Answer

Answer: c [Reason:] Horizontal digester, multi- tube (2-8 digester). Screw feed. Kraft pulping of sawdust. Semi-chemical pupling of chips, non-woods (straw), short cooking times.

9. Fill in the blank.
___________ in liquor=(percent chemical on wood)/(liquor to wood ratio)
a) Chemical concentration
b) Pulping liquor mass
c) Chemical charge
d) Liquor to wood ratio

View Answer

Answer: a [Reason:] The chemical concentration is the measure of concentration of the pulping chemical in the liquor.

10. Fill in the blank.
__________ = (total pulping liquor mass)/(dry wood mass)
a) Wood to pulp ratio
b) Liquor to wood ratio
c) Delignification selectivity
d) Defiberating

View Answer

Answer: b [Reason:] The liquor to wood ratio, liquor : wood is normally expressed as a ratio: typically, it has a value 3:1 to 4:1 in full chemical pulping.

Set 5

1. What is the name of the process where chips are impregnated with cooking liquor, the free liquor is drained or otherwise removed.
a) Vapor-phase pulping
b) Liquid-phase pulping
c) Saturated-phase pulping
d) Differential-phase pulping

View Answer

Answer: a [Reason:] Vapor-phase pulping is the name of the process where chips are impregnated with cooking liquor, the free liquor is drained or otherwise removed.

2. What is the name of the process which involves steps like mild chemical treatment and followed by moderate mechanical refining.
a) Semi-chemical process
b) Vapor-chemical process
c) Differential-chemical process
d) Saturated-chemical process

View Answer

Answer: a [Reason:] Semi-chemical pulping is the name of the process which involves steps like mild chemical treatment followed by moderate mechanical refining are executed.

3. What is the range of yield in the Semi-chemical process?
a) 70-95%
b) 60-80%
c) 30-40%
d) 55-65%

View Answer

Answer: b [Reason:] 60-80% is the yield of the Semi-chemical process. It is because of its two phase expansion process.

4. High yield chemical pulling is the other name of semi-chemical process.
a) True
b) False

View Answer

Answer: a [Reason:] This is named so, because the yield is 60-80%.

5. Natural Sulfite Semi-Chemical is the full form of N.S.S.C. process. This is the most common method.
A) True
B) False

View Answer

Answer: b [Reason:] The full form of N.S.S.C. is Neutral Sulfite Semi-Chemical process.

6. What does NSSC cooking liquor contain?
a) CTMP+BOD
b) CTMP+APMP
c) APMP+BOD
d) Na2So3+Na2Co3

View Answer

Answer: d [Reason:] It uses 10-15% of the chemical charge to act as a buffer. The pH is 7-10.

7. The de-fiberator is also known as?
a) Cold stock refiner
b) Hot stock refiner
c) Neutral stock refiner
d) Maximum stock refiner

View Answer

Answer: b [Reason:] The de-fiberator is also known as ‘Hot stock refiner’. It’s an attrition mill as make-up chemical in kraft recovery plant.

8. The _________ liquor semi-chemical pulping process for corrugating medium uses green liquor as the pulping liquor.
a) Green
b) Distilled
c) Pure
d) Indigo

View Answer

Answer: a [Reason:] The green liquor semi-chemical pulping process is for corrugating medium and uses green liquor as the pulping liquor. The green liquor can be obtained from the associated kraft mill.

9. __________ is the use of waste liquor of a semi-chemical mill as the make-up chemical in the kraft recovery plant.
a) Diagonal recovery
b) Cross recovery
c) Multi recovery
d) Instant recovery

View Answer

Answer: b [Reason:] Cross recovery is the use of waste liquor of a semi- chemical mill as the make-up chemical in the kraft recovery plant.

10. The low ________ removal makes chemical recovery difficult in the semi-chemical process.
a) Lignin
b) Pulp
c) Hardwood
d) Softwood

View Answer

Answer: a [Reason:] The low lignin removal makes chemical recovery difficult in the semi-chemical process. The low lignin removal makes chemical recovery difficult.