Category: Pulp & Paper Objective Questions

Pulp and Paper Multiple Choice Questions on “Ink and Ink Applications”.

1. Ink consists of pigments or dyes, a vehicle (binder) to attach the pigment to the paper
a) True
b) False
Answer: a
Clarification: Ink consists of pigments or dyes, a vehicle (binder) to attach the pigment to the paper, and include solvents for faster drying and ink additives.

2. Ink consists of pigments such as __________ to supply color and opacity and a vehicle to carry the pigment and bind it to the paper.
a) Silicon oxide
b) Aluminium oxide
c) Titanium oxide
d) Zinc oxide
Answer: c
Clarification: The main utilize of TiO₂ is as a white powder pigment because of its brightness and very high refractive index. Pigments should be insoluble in H₂O and the ink formulation to prevent running.

3. Pigments which are _________ variant of organic dyes are called vat dyes.
a) Soluble
b) Insoluble
c) Acidic
d) Basic
Answer: b
Clarification: Vat dyes are essentially insoluble in H₂O and incapable of dyeing fibres directly. However, reduction in alkaline liquor produces the H₂O-soluble alkali metal salt of the dye, which, in this leuco form, has a similitude for the textile fibre.

4. Ink __________ are often heavy metal salts of (unsaturated fatty acid) soaps that promote oxidation and/or polymerization.
a) Ink paper sizing
b) Ink receptivity
c) Ink additives
d) Ink visibility
Answer: c
Clarification: Printing inks and overprint varnishes require good wetting of various substrates, excellent surface protection and defoaming, and good pigment stabilization. Paraffin-based wax emulsion for aq. coatings, printing inks as well as care products and polishes for improving H₂O repellency and surface slip.

5. __________ of the ink vehicle leaves the solid ink with rosin esters and metal binders behind; this is utilized in magazine and catalogue grades utilizing letterpress or heat set web offset printing.
a) Sublimation
b) Liquation
c) Evaporation
d) Solidification
Answer: c
Clarification: To keep heating costs low, solvents with low boiling points, but not so low as to be unsafe, are utilized. The ink further sets by cooling to ambient temperatures.

6. __________ of a drying oil with multifunctional carboxylic acids and alcohols left on the paper surface after the vehicle is absorbed into the paper might promote polymerization.
a) Oxidation
b) Reduction
c) Radiation
d) Cracking
Answer: a
Clarification: Heavy metals (cobalt, manganese, lead) might promote oxidation with atmospheric O₂. Since oxidation is the key to curing in these oils, those that are susceptible to chemical drying are often unsuitable for cooking, and are also highly susceptible to becoming rancid through autoxidation, the process by which fatty foods develop off-flavors.

7. __________ curing cautilizes monomers or pre-polymers in the vehicle to form polymers; it’s useful with acrylics.
a) Oxidation
b) Reduction
c) Radiation
d) Cracking
Answer: c
Clarification: They cure by air oxidation when O₂ from the air reacts with unsaturated fatty acids in their drying oils. This method doesn’t have much utilize with paper, but is often utilized for metal and plastic substrates to avoid the utilization of large ovens.

8. Infrared hardening , precipitation of binders, gelation, and cooling of hot thermoplastic inks utilized in electrostatic printing.
a) True
b) False
Answer: b
Clarification: Infrared hardening , precipitation of binders, gelation, and cooling of hot thermoplastic inks utilized in electrostatic printing like photocopy and laser printers are other mechanisms utilized less often, but are decreasing in utilize.

9. __________ is the amount of paper that could be covered by ink to achieve a specified print density under operating conditions of a press.
a) Ink tack
b) Ink mileage
c) Ink additives
d) Ink visibility
Answer: b
Clarification: It is measured in English units of square inches per pound of ink. The concept could be developed as an input-transform-output equation. On the input side is ink of correct color and strength.

10. ____________ is a measure of the force or energy required to split a film of ink. In this regard the ink is like a contact adhesive.
a) Ink tack
b) Ink mileage
c) Ink additives
d) Ink visibility
Answer: a
Clarification: It’s an crucial aspect in the printing process that needs to be monitored for quality control. If a high force is required to split a film of ink, it might cautilize picking of the paper.

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Pulp and Paper Multiple Choice Questions on “Sensors”.

1. A __________ for a given process must have at least one sensor, the controller, and a control element to which the results are applied.
a) Control loop
b) Kraft loop
c) Automatic loop
d) Pausing loop
Answer: a
Clarification: The automatic control is where a machine or electronic circuit is the control as opposed to a human being is the control loop. The controller that decides what’s to be done with the information that is collected, and a control element to which the results are applied.

2. A good example of automatic control is electric heating of a house in a cold environment, a process where a single variable is controlled.
a) True
b) False
Answer: a
Clarification: When the temperature drops below the set point a switch (controller) is closed and the heater (control element) comes on. When the temperature rises above the set point, the switch opens and the heater is turned off.

3. This is __________ feedback loop because the desired result is determined and the information fed back to the controller for appropriate action. This system is also known as __________ control loop.
a) 1i process
b) 2i process
c) 3i process
d) 4i process
Answer: b
Clarification: A feedback loop is a term commonly utilized in economics to indicate to a situation where part of the output of a situation is utilized for new input. An example of a positive feedback loop would be one where success feeds success.

4. The difference between the actual value and the set point is known as the __________ The controller reads the __________ and makes a decision.
a) Sensor
b) Top
c) Point
d) Error
Answer: d
Clarification: The action taken could be very simple to very complicated, depending on the system and the size of the acceptable error. The statistics error refers to the diff. b/w the value which has been computed and the correct value.

5. The __________ is a device which converts a change in a parameter to a change in a electric or pneumatic signal.
a) Sensor
b) Top
c) Point
d) Error
Answer: a
Clarification: It’s a type of transducer which is a device that changes a signal from one form to another form, such as a change in light to a change in voltage or a change in voltage to a change in current.

6. A transfer function relates the value of the parameter to be measured with the output of the __________
a) Sensor
b) Top
c) Point
d) Error
Answer: a
Clarification: Typically it is a representation in terms of spatial or temporal frequency, of the relation b/w the input and output of a linear time-invariant system with zero initial conditions and zero-point equilibrium. With optical imaging devices, for example it is the Fourier transform of the point spread function i.e., the intensity distribution cautilized by a point object in the field of view.

7. The __________ of a sensor is a measure of how the sensor responds to an actual change as a function of time. For example, all thermocouples have mass.
a) Size
b) Material
c) Time response
d) Durability
Answer: c
Clarification: The order of a control system is determined by the power of sensor in the denominator of its transfer function If the power of sensor in the denominator of transfer function of a control system is 2, then the system is said to be second-order control system.

8. The __________ at one temperature is immersed in a liq. of a different temperature, the output of the __ would change with time until it finally gives a reading that is around its normal error.
a) Thermocouple
b) Photoconductors
c) Photovoltaic
d) Piezoelectric
Answer: a
Clarification: A thermocouple is an electrical device consisting of 2 different conductors forming electrical junctions at differing temperature It produces a temperature-dependent voltage as a result of the thermoelectric effect, and this voltage could be interpreted to measure temperature

9. __________ utilise a thin band of a material that becomes conductive when exposed to light of a minimum frequency.
a) Thermocouple
b) Photoconductors
c) Photovoltaic
d) Piezoelectric
Answer: b
Clarification: It’s an optical and electrical phenomenon in which a material becomes more electrically conductive because of the absorption of electromagnetic radiation such as visible light or gamma radiation. Whenever light is absorbed by a material such as a semiconductor, the number of free electrons and electron holes inc. and raises its electrical conductivity.

10. ____________ cells produce a voltage and current that are a function of the light level incident to them. These have time constants on the order of 1 to 100 µs.
a) Thermocouple
b) Photoconductors
c) Photovoltaic
d) Piezoelectric
Answer: c
Clarification: Photovoltaics (P.V.) covers the conversion of light into electricity utilizing semiconducting materials that manifests the photovoltaic effect, a phenomenon studied in physics, photochemistry, and electrochemistry. For very less levels of light utilized in liq. scintillation counters to determine radioactivity photomultiplier tubes are utilized.

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Pulp and Paper Multiple Choice Questions and Answers (MCQs) on “Wood Chips Preparation and Handling at the Pulp Mill”.

1. What is the purpose of barker?
a) Remove bark from wood after chipping
b) Remove bark from wood before chipping
c) Add a bark like layer before chipping
d) Add a bark like layer after chipping
Answer: b
Clarification: bark is not useful as it has negligible fiber. It darkens pulp, requires extra chemical usage and introduces contaminations. Hence bark is removed from wood before chipping.

2. What type of barker is this?

a) Drum
b) Hydraulic
c) Rosewood
d) Aviato
Answer: a
Clarification: large rotating steel drum mounted with exit lower than the entrance to promote flow of logs.

3. A dam controls log retention time in drum barker.
a) True
b) False
Answer: a
Clarification: A dam at exit controls the log retention time, which is of the order of 20 – 30 minutes.

4. Which type of barker is ideal for small mills.
a) Hydraulic
b) Drum
c) Rosserhead
d) Aviato
Answer: c
Clarification: In this logs are fed individually. It is a slow process suitable for frozen logs.

5. Waste water from hydraulic barker is higher in ______________
a) LRP
b) CRP
c) NPR
d) BOD

View Answer

Answer: d
Clarification: It is a type of pollutant which needs to the treated before discharging.

6. Which are the two types of barkers in the following?
a) Flat
b) Slasher deck
c) Flail
d) Cylinder
Answer: c
Clarification: Uses a rotating cylinder with numerous chains hanging from it to delimb and debark small diameter material.

7. Is Softwood easier to chip and generate fewer fine chips?
a) True
b) False
Answer: b
Clarification: It is because Hardwood is in a more dry and hard form than Softwood.

8. Arrange this in proper downward order
a) Oversized – Over thick – Accepts – Pins – Fines
b) Oversized – Over thick – Pins – Accepts – Fines
c) Over thick – Oversized – Accepts – Pins – Fines
d) Fines – Over thick – Accepts – Pins – Oversized
Answer: a
Clarification: This is ideal chip size distribution analysis for perfect functioning.

9. _____________ are the chip fraction of the ideal size distribution analysis perfect for pulping.
a) Pins
b) Accepts
c) Rejects
d) Fines
Answer: b
Clarification: These chips pass through a 8 or 10mm slotted screen and are retained on a screen with holes.

10. At the bottom of the pass __________ are collected?
a) Fines
b) Pin
c) Accepts
d) Silth
Answer: a
Clarification: The definition of fines varies with mill species, but fines generally consist of material passing through 3mm screen

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Pulp and Paper Multiple Choice Questions on “Pulp Washing”.

1. Pulp washers are also known as ‘Black stock washers’.
a) True
b) False
Answer: a
Clarification: Pulp washers are called so because of the color of the raw material which is utilized to feed the tank. The crude material is of dirty black color which is then washed.

2. Pulp washers use counter-current flow between stages such that the pulp moves opposite in direction to the flow of wash water.
a) True
b) False
Answer: b
Clarification: This design allows for the most removal of pulping material and the lignin with the least amount of water.

3. Following the reason behind the removal of lignin in Pulp washers:-
a) To reduce bleaching chemical demand
b) To increase bleaching chemical demand
c) To maintain constant bleaching chemical demand
d) To freeze bleaching chemical demand
Answers: a
Clarification: To reduce bleaching chemical demand. This is done to improve paper making with brown papers.

4. The dilution factor is a measure amount of ___________ used in washing.
a) Acid
b) Base
c) Water
d) Salt
Answer: c
Clarification: The dilution factor is a measure of the amount of water used for washing. It’s compared to the amount theoretically required to displace the liquor from the thickened pulp.

5. Following is the way to calculate dilution factor:-
a) Mass of water per unit mass of dry pulp
b) Mass of acid per unit mass of dry pulp
c) Mass of buffer solution per unit mass of dry pulp
d) Mass of base per unit mass of dry pulp
Answer: a
Clarification: The dilution factor is a measure of the amount of water used in washing. It is compared to the amount theoretically required to displace the liquor from the thickened pulp.

6. Low dilution factor ___________ the energy requirements of the multiple effects evaporators.
a) Increases
b) Decreases
c) Freezes
d) Skips
Answer: b
Clarification: Low dilution factor decrement the energy requirements of the multiple effects evaporators. Using more washers increment removal of pulping chemicals with less water dilution but increment capital and operating costs.

7. The soda loss in pulp is traditionally measured as ___________ pulp on a Na₂SO₄ basis.
a) Kg/lb
b) Lb/kg
c) Lb/ton
d) Ton/lb
Answer: c
Clarification: The soda loss in pulp is traditionally measured as lb/ton pulp on a Na₂SO₄ basis.

8. A ___________ is used to siphon the water from the washer so that a vacuum pump is not usually required.
a) Drop hand
b) Drop leg
c) Drop finger
d) Drop thumb
Answer: b
Clarification: A drop leg is used to siphon the water from the washer so that a vacuum pump is not usually required. The bottom leg goes to a filtrate storage tank that is designed to prevent air from entering.

9. The vacuum supplied by drop leg for the first stage is of range ___________
a) 12kPa
b) 15kPa
c) 20kPa
d) 24kPa
Answer: d
Clarification: A drop leg is used to siphon the water from the washer so that a vacuum pump is not usually required. The bottom leg goes to a filtrate storage tank that is designed to prevent air from entering.

10. Drop leg is ideally a vertical drop. It’s horizontal section is a needed, and it should be exactly horizontally placed at least __________m below the washer.
a) 1
b) 5
c) 55
d) 7
Answer: d
Clarification: Drop leg is ideally a vertical drop. It’s horizontal section is needed which should be horizontally placed at least 7 m below the washer. Drop legs that are not entirely horizontal or vertical allow air to separate from the stock and rush upward, thereby accumulating and decreasing the vacuum.

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Pulp and Paper Multiple Choice Questions on “Basic Optical Tests of Paper”.

1. ___________ is the measure of the hue or chroma of light reflected from the surface of paper.
a) Pigment
b) Colour
c) Opacity
d) Brightness
Answer: b
Clarification: Colour is the measure of the hue or chroma of light reflected from the surface of paper. It cannot be easily put in numbers, and it is frequently expressed descriptively, as “red” or “blue”. Colour of paper can be expressed by a series of three numbers in the International scale (C.I.E.) system, x, y, and z.

2. ___________ is a measure of the “whiteness” of paper. These methods are not applied to coloured papers that are characterized with the tests. The ___________ is the % of diffuse reflected light from a thick pad of paper to visible light.
a) Pigment
b) Colour
c) Opacity
d) Brightness
Answer: d
Clarification: Brightness is a measure of the “whiteness” of paper. These methods are not applicable to coloured papers that are characterized with the tests described above. Precisely, brightness is the % of diffuse reflected light from a thick pad of paper to visible light at a wavelength of 457 nm. This brightness is designated as R(infinity).

3. What is the name of the instrument?

a) H.G. Brightness
b) L.K. Brightness
c) M.K.L. Brightness
d) P.L. Brightness
Answer: a
Clarification: In the G.E. brightness, the light is illuminated on the paper at a 45 degree angle and the reflected light at 0 degree’s measured. If an ultraviolet source’s utilized, the effect of fluorescent dyes, the optical brighteners, can also be measured.

4. What is the name of the instrument?

a) H.G. Brightness
b) Elrepho test
c) Opacity test
d) Colour test
Answer: b
Clarification: In the Elrepho test , light source diffuse and the reflected light is measured at right angle from the surface of the paper. The diffuse light source’s a sphere coated with TiO₂ from which light from 2 light bulbs reflects.

5. ___________ is the ability of paper to hide or mask a colour or object in back of the sheet. A high _________ in printed paper allows us to read the front side of the page without being distracted by print images upon the back side.
a) Brightness
b) Colour
c) Opacity
d) Gloss
Answer: c
Clarification: Opacity is the ability of paper to hide a colour or object in back of the sheet. A high opacity in printed paper allows us to read the front side of the page without being distracted by print images upon the back side.

6. What is the name of the hidden part?

__________= (R₀) / (R_∞) x 100%

a) TAPPI opacity
b) Printing opacity
c) Solid opacity
d) Chroma opacity
Answer: b
Clarification: Printing opacity is the ability of paper to mask a colour or object in back of the sheet. A high opacity in printed paper allows one to read the front side of the page.

7. What is the name of the hidden part?

__________= (R₀) / (R_0.89) x 100%

a) T.A.P.P.I. opacity
b) Solid opacity
c) Chroma opacity
d) Printing opacity
Answer: a
Clarification: T.A.P.P.I opacity is the ability of paper to hide or mask a colour or object in back of the sheet. A high opacity in printed paper allows one to read the front side.

8. ___________ is a measure of the sheen or polish of paper.
a) Opacity
b) Brightness
c) Colour
d) Gloss
Answer: d
Clarification: Gloss is a measure of the sheen or polish of paper. It’s measured by illuminating the paper at a very low angle and measuring the reflectance at a similar low angle.

9. __________ pulps are of especially high opacity. Fillers tend to have high indices of refraction and provide interfaces for light scattering as well. The very high index of refraction of Ti₂ allows thin papers to have high opacity as in the case of bible papers.
a) Rosewood pulps
b) Groundwood pulps
c) Roughwood pulps
d) Lignin-free wood pupls
Answer: b
Clarification: Stone groundwood pulps are of especially high opacity. Fillers tend to have high indices of refraction and provide interfaces for light scattering as well. The very high index of refraction of Ti₂allows thin papers to have high opacity as in the case of bible papers.

10. Putting a wooden stick in clear water at an angle; the stick appears to be bend at the water-air interface. What is the property we are talking about here?
a) Gloss
b) Brightness
c) Opacity
d) Illuminating
Answer: c
Clarification: The classic example’s putting a wooden stick in clear water at an angle; the stick appears to bend at the water-air interface. Rough, non-flat surfaces help scatter the light in all different direction.

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Pulp and Paper Multiple Choice Questions and Answers (MCQs) on “Wood Moisture Content and Density”.

1. The specific gravity (specific gravity) of wood’s the oven-dry weight of wood divided by the weight of _________ of H₂O.
a) Mass
b) Density
c) Volume
d) Viscosity
Answer: c
Clarification: This produces a unitless number. The displaced volume of H₂O can be calculated by the volume of the wood if it’s of even shape such as a rectangular block.

2. The basic sp. gr. of woods is commonly b/w 0.35 and 0.60, but can change from 0.2 – 0.7.
a) True
b) False
Answer: a
Clarification: The basic sp. gr. of cell wall material’s approx. 1.50. The basic specific gravity of woods is commonly b/w 0.35 and 0.60, but can vary from 0.2 to 0.7.

3. The viscosity of a material’s defined as the mass/unit volume.
a) True
b) False
Answer: b
Clarification: The density of a material is defined as the mass/volume. When the units of pounds or ounces are utilized one actually obtains a weight density. For wood, it’s customary to take the total mass / by the volume both at the same moisture content.

4. The _________of wood’s a measure of the H₂O content relative to either the total wet weight of material or to the weight of oven dried wood material.
a) Over-dry weight
b) Specific gravity
c) Moisture content
d) Green weight
Answer: c
Clarification: The moisture content of wood’s a measure of the H₂O content relative to either the net wet weight of material the green weight of wood or to the weight of oven dried wood material the oven-dry basis.

5. After converting 20% MC_QD to MC_QR the value would be _________
a) 10%
b) 15%
c) 5%
d) 17%
Answer: d
Clarification: One could come up with about 17% MC_GR. Or else, one could solve it for 16.7% MC_GR. 20% MC_QD means 20 parts H₂O to 100 parts dry wood; this, in turn, means 20 parts water for 120 parts wet wood or 16.7% MC_QR.

6. A sample of wet Douglas-fir wood 20 mm thick, 50 mm wide and 10 cm long weighs 90.21 g. It is then dried at 105°Celcius to constant weight and re-weighed after cooling in a desiccator. The oven-dry weight is 44.37 g. What are the MC_GR, MC_QD, and basic specific gravity of the wood sample?
a) 1%, 10%, and 0.333
b) 75.2%, 103.8%, and 1.555
c) 4.8%, 106.2%, and 6.254
d) 50.8%, 103.8%, and 0.444
Answer: d
Clarification:
MC_GR= (90.21 – 44.37) / 90.21 x 100%= 50.8%
MC_OD= (90.21 – 44.37) / 44.37 x 100%= 103.3%
sp. gr.= (44.37 / 2x5x10) / 1= 0.444

7. What is the name of the hidden part?

a) Overdry weight of wood
b) Wet weight of wood
c) Weight of wood in sodium
d) Weight of lignin
Answer: a
Clarification: Here moisture contents over 100 percent are possible and commonly encountered. The moisture content of wood (green basis) is typically 50 percent, but varies from 30 – 60 percent. This tie in to 0.43 to 1.5 kg H₂O per kg dry wood, (43-150 percent MC_QD).

8. What is the name of the hidden part?

a) 100%-MC_GR
b) MC_OD-100%
c) 100%+MC_GR
d) MC_OD+100%
Answer: a
Clarification: Here moisture contents over 100 percent are possible and commonly encountered. The moisture content of wood (green basis) is typically 50 percent, but varies from 30 – 60 percent. This tally to 0.43 to 1.5 kg H₂O per kg dry wood, (43-150 percent MC_QD).

9. What is the name of the hidden part?

MC _GR = {(weight of water in wood) / (________)} x 100%

a) Overdry weight of wood
b) Wet weight of wood
c) Weight of wood in sodium
d) Weight of lignin
Answer: b
Clarification: Here moisture contents over 100 percent are possible and commonly encountered. The moisture content of wood (green basis) is typically 50 percent, but varies from 30 – 60 percent. This consonant to 0.43 to 1.5 kg H₂O per kg dry wood, (43-150 percent MC_OD).

10. What is the name of the hidden part?

MC_GR = {(MC_OD) / (_______)} x 100%

a) 100%-MC_GR
b) MC_OD-100%
c) 100%+MC_GR
d) MC_OD+100%
Answer: d
Clarification: Here moisture contents over 100 percent are possible and commonly encountered. The moisture content of wood (green basis) is typically 50 percent, but varies from 30 – 60 percent. This coincide to 0.43 to 1.5 kg H₂O per kg dry wood, (43-150 percent MC_OD). .

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