Multiple choice question for engineering
Set 1
1. The analysis of electromagnetic radiation scattered, absorbed or emitted by the molecule is called
a) Kaleidoscopy
b) Astronomy
c) Spectroscopy
d) Anatomy
Answer
Answer: c [Reason:] The analysis of electromagnetic radiation scattered, absorbed or emitted by the molecule is called spectroscopy. Astronomy, is the study of celestial objects and processes the physics, chemistry, and evolution of such objects and processes. A kaleidoscope is an optical instrument, typically a cylinder with mirrors containing loose, colored objects such as beads or pebbles and bits of glass. Anatomy is the branch of biology concerned with the study of the structure of organisms and their parts.
2. The energy level with lower energy is called
a) Ground state energy level
b) Initial state energy level
c) Excited state energy level
d) All of the mentioned
Answer
Answer: a [Reason:] The lower energy level is called ground state and the higher energy level is called excited state. The excited state of a system (such as an atom, molecule or nucleus) is any quantum state of the system that has a higher energy than the ground state.
3. Absorption spectrum results when an electron in an atom undergoes a transition from
a) Higher energy level to lower one
b) Lower energy level to higher one
c) Intermediate levels
d) All of the mentioned
Answer
Answer: b [Reason:] Absorption spectrum results when an electron in an atom undergoes a transition from lower energy level to higher one.
4. The energy of a photon is given by
a) h/ν
b) ν/h
c) 1/hν
d) hν
Answer
Answer: d [Reason:] The energy of a photon is given by hν where ν is the frequency and h is plank constant.
5. Select the incorrect statement from the following option.
a) Emission spectrum results when an electron in an atom undergoes a transition from excited state to the ground state
b) In the emission spectrum, transition takes place with the emission of a photon of energy hν
c) In the emission spectrum, transition takes place with the absorption of a photon of energy hν
d) All of the mentioned
Answer
Answer: c [Reason:] In the emission spectrum, transition takes place with the emission of a photon of energy hν. All the other options are correct. Emission spectrum results when an electron in an atom undergoes a transition from excited state to the ground state.
6. The spectra can be broadly classified into two categories. They are
a) Atomic and molecular spectra
b) Atomic and electronic spectra
c) Molecular and electronic spectra
d) None of the mentioned
Answer
Answer: a [Reason:] The spectra can be broadly classified into two categories: atomic and molecular spectra. Atomic spectra is the spectrum of frequencies of electromagnetic radiation emitted or absorbed during transitions of electrons between energy levels within an atom. Molecular spectra arises from the transition of an electron between the molecular energy levels.
7. State true or false. In atomic spectroscopy, only electronic transitions are involved.
a) True
b) False
Answer
Answer: a [Reason:] In atomic spectroscopy, only electronic transitions are involved. It is the spectrum of frequencies of electromagnetic radiation emitted or absorbed during transitions of electrons between energy levels within an atom.
8. Select the correct statement from the following options.
a) Molecular spectra arises from the transition of an electron between the molecular energy levels
b) In molecular transitions, electronic, rotational and vibration transitions occurs
c) Molecular spectra is more complicated than atomic spectra
d) All of the mentioned
Answer
Answer: d [Reason:] Molecular spectra arises from the transition of an electron between the molecular energy levels. In molecular transitions, electronic, rotational and vibration transitions occurs and molecular spectra is more complicated than atomic spectra.
9. The necessary condition for absorption spectrum is that
a) hν should be greater than energy difference
b) hν should be smaller than energy difference
c) hν should be equal to the energy difference
d) None of the mentioned
Answer
Answer: c [Reason:] The necessary condition for absorption spectrum is that hν should be equal to the energy difference(ΔE = Ee – Eg).
10. State true or false. Spectroscopy deals with the transition that a molecule undergoes on absorption of suitable radiations determined by quantum mechanical selection rules.
a) True
b) False
Answer
Answer: a [Reason:] Spectroscopy deals with the transition that a molecule undergoes on absorption of suitable radiations determined by quantum mechanical selection rules. The spectra can be broadly classified into two categories: atomic and molecular spectra.
Set 2
1. The physical mixture of two or more polymers that are not linked by covalent bonds is called
a) Polymerisation
b) Dendrimer
c) Polyblend
d) Multiblend
Answer
Answer: c [Reason:] The physical mixture of two or more polymers that are not linked by covalent bonds is called polyblend or polymer blend. They are blended together to create a new material with different physical properties.
2. Polymers are dissolved in common solvent to give
a) Mechanical blends
b) Solution-cast blends
c) Latex blends
d) Chemical blends
Answer
Answer: b [Reason:] Polymers are dissolved in common solvent to give solution-cast blends. If the blend is made of two polymers, two glass transition temperatures will be observed.
3. For amorphous and semi-crystalline polymers, mixing leads to the formation of
a) Mechanical blends
b) Solution-cast blends
c) Latex blends
d) Chemical blends
Answer
Answer: a [Reason:] For amorphous and semi-crystalline polymers, mixing leads to the formation of mechanical blends. The macroscopically uniform properties are usually caused by sufficiently strong interactions between the component polymers.
4. The immiscible blends exhibit
a) Excellent mechanical properties
b) Poor mechanical properties
c) Poor chemical properties
d) Intermediate chemical properties
Answer
Answer: b [Reason:] The immiscible blends exhibit poor mechanical properties. This is by far the most populous group. If the blend is made of two polymers, two glass transition temperatures will be observed.
5. Cross-linked polymers is swollen with different monomer, which results in
a) Mechanical blends
b) Solution-cast blends
c) Latex blends
d) Chemical blends
Answer
Answer: d [Reason:] Cross-linked polymers is swollen with different monomer, which results in chemical blends. They have different chemical properties.
6. Select the incorrect option from the following option.
a) Immiscible blends are usually opaque
b) Immiscible blends exhibit a single glass transition temperature (Tg) intermediate between those of individual components
c) Miscible blends are usually clear
d) Immiscible blends exhibit separate Tg’s characteristics of each component
Answer
Answer: b [Reason:] Miscible blends exhibit a single glass transition temperature (Tg) intermediate between those of individual components. All the other options are correct.
7. State true or false. (PPO + PS) polyblend is commercially available engineering plastic Noryl (General Electric).
a) True
b) False
Answer
Answer: a [Reason:] (PPO + PS) polyblend is commercially available engineering plastic Noryl (General Electric). The use of the term polymer alloy for a polymer blend is discouraged, as the former term includes multi-phase co-polymers but excludes incompatible polymer blends.
8. Fine dispersions of polymers in water is mixed and coagulated to give
a) Mechanical blends
b) Solution-cast blends
c) Latex blends
d) Chemical blends
Answer
Answer: c [Reason:] Fine dispersions of polymers in water is mixed and coagulated to give latex blends. The use of the term polymer alloy for a polymer blend is discouraged, as the former term includes multi-phase co-polymers but excludes incompatible polymer blends.
9. The blend is said to be synergistic for the mechanical property if the term (I) in the empirical formula is
a) Zero
b) Positive
c) Negative
d) Imaginary
Answer
Answer: b [Reason:] The blend is said to be synergistic for the mechanical property if the term (I) in the empirical formula is positive. For amorphous and semi-crystalline polymers, mixing leads to the formation of mechanical blends.
10. The blend is said to be additive for the mechanical property if the term (I) in the empirical formula is
a) Imaginary
b) Positive
c) Negative
d) Zero
Answer
Answer: d [Reason:] The blend is said to be additive for the mechanical property if the term (I) in the empirical formula is zero. For amorphous and semi-crystalline polymers, mixing leads to the formation of mechanical blends.
Set 3
1. A polymer is any substance made up of many repeating units called
a) Resins
b) Plastic
c) Mers
d) Blocks
Answer
Answer: c [Reason:] A polymer is any substance made up of many repeating units, building blocks called mers. Polymers are made up of many many molecules all strung together to form really long chains.
2. Small molecules which combine to form polymer are called
a) Resins
b) Monomers
c) Plastic
d) Blocks
Answer
Answer: b [Reason:] Small molecules which combine with each other to form polymer are called monomers. Polymers are made up of many many molecules all strung together to form really long chains.
3. Select the incorrect statement from the following options.
a) When in form ready for further working, polymers are called resins
b) The chemical process leading to the formation of polymer is known as polymerisation
c) The number of monomeric units contained in polymer is called degree of polymerisation
d) Due to their small size, polymers are also called micro-molecules
Answer
Answer: d [Reason:] Due to their large size, polymers are also called macro-molecules. All the other options are correct. When in form ready for further working, polymers are called resins. The chemical process leading to the formation of polymer is known as polymerisation and the number of monomeric units contained in polymer is called degree of polymerisation.
4. State true or false. Below threshold degree of polymerisation (DP), the polymer does not possess any strength and exist either as liquid resin or friable powder.
a) True
b) False
Answer
Answer: a [Reason:] Below threshold degree of polymerisation, the polymer does not possess any strength and exist either as liquid resin or friable powder. The number of monomeric units contained in polymer is called degree of polymerisation.
5. The optimum DP value of cellulose is
a) 150
b) 250
c) 400
d) 500
Answer
Answer: b [Reason:] The optimum DP value of cellulose is 250. The number of monomeric units contained in polymer is called degree of polymerisation (DP).
6. The functionality of ethylene glycol is
a) 2
b) 3
c) 4
d) 5
Answer
Answer: a [Reason:] The functionality of ethylene glycol is 2. It is a colorless, odorless, viscous dihydroxy alcohol and has sweet taste, but is poisonous if ingested.
7. Which of the following polymer is not classified under the category of configuration?
a) Syndiotactic
b) Atactic
c) Cross-linked
d) Isotactic
Answer
Answer: c [Reason:] Cross-linked polymer is not classified under the category of configuration. Syndiotactic, atactic and isotactic are classified under the category of configuration. Tacticity is the relative stereochemistry of adjacent chiral centers within a macromolecule.
8. Which of the following is not an example of semi-crystalline polymer?
a) HDPE
b) Nylon
c) Polyesters
d) LDPE
Answer
Answer: d [Reason:] LDPE is not an example of semi-crystalline polymer. It is an example of branched amorphous polymer. All the other options are examples of semi-crystalline polymer.
9. Styrene acrylonitrile is an example of
a) Co-polymer
b) Homopolymer
c) Linear polymer
d) Amorphous polymer
Answer
Answer: a [Reason:] Styrene acrylonitrile resin is a copolymer plastic consisting of styrene and acrylonitrile. It is also known as SAN. It is widely used in place of polystyrene.
10. Which of the following polymer is not classified under the category of end use?
a) Fibers
b) Adhesives
c) Elastomers
d) Synthetic
Answer
Answer: d [Reason:] Synthetic polymer is not classified under the category of end use. It is classified under the category of origin. Fibers, adhesives and elastomers are classified under the category of end use.
11. Select the incorrect statement from the following option.
a) Thermosets are formed by condensation polymerisation reactions
b) Thermosets have 3-D, cross-linked network structure
c) Thermosets soften on heating and stiffen on cooling
d) Thermosets are generally insoluble in any solvent
Answer
Answer: c [Reason:] Thermosets do not soften on heating. All the other options are correct. Thermosets are formed by condensation polymerisation reactions, have 3-D, cross-linked network structure and are generally insoluble in any solvent.
12. Which one of the following is not an example of thermoplastic?
a) Polyvinyl chloride
b) Nylon
c) Polyesters
d) Epoxy
Answer
Answer: d [Reason:] Epoxy is not an example of thermoplastic. It is an example of thermoset polymer. Polyvinyl chloride, nylon and polyesters are the examples of thermoplastic.
13. The weight average molecular weight for PP given its degree of polymerisation as 10,000 will be
a) 3,00,000 gm/mol
b) 4,20,000 gm/mol
c) 6,70,000 gm/mol
d) 8,40,000 gm/mol
Answer
Answer: b [Reason:] The weight average molecular weight for PP given its degree of polymerisation as 10,000 will be 4,20,000 gm/mol.
14. The cryoscopy refers to
a) Osmotic pressure measurement
b) Elevation in boiling point measurement
c) Freezing point depression measurement
d) Increase in solubility measurement
Answer
Answer: c [Reason:] The cryoscopy refers to freezing point depression measurement. A technique for determining the molar concentration of a solution by measuring the freezing point.
15. State true or false. Higher molecular weight polymers are tougher and more heat resistant.
a) True
b) False
Answer
Answer: a [Reason:] Higher molecular weight polymers are tougher and more heat resistant. Polymeric mixtures are far less miscible than mixtures of small molecule materials.
Set 4
1. Which of the following does not combine with fiber to give composites?
a) Metals
b) Ceramics
c) Non-metals
d) Polymers
Answer
Answer: c [Reason:] Composites are obtained from metals, ceramics and polymers by adding fibers to them. Non-metals do not contribute in the formation of composites.
2. Which of the following is not a property of matrix materials which are modified by adding particulate fillers?
a) Improved performance at elevated temperature
b) Decrease in surface hardness
c) Modification in electrical conductivity
d) Improved abrasion resistance
Answer
Answer: b [Reason:] Improved performance at elevated temperature, decrease in surface hardness, modification in electrical conductivity, improved abrasion resistance are some of the properties of matrix materials which are modified by adding particulate fillers.
3. What is aspect ratio?
a) Length to diameter ratio
b) Length to depth ratio
c) Depth to length ratio
d) Diameter to length ratio
Answer
Answer: a [Reason:] Aspect ratio is defined as length to diameter ratio. The aspect ratio is expressed as two numbers separated by a colon (x:y). The values x and y do not represent actual length and diameter but, rather, the relationship between length and diameter.
4. Which of the following type of composite is not classified under the category of number of layers?
a) Unidirectional fibre reinforced
b) Laminar
c) Sandwich panels
d) Glass-fibre reinforced
Answer
Answer: d [Reason:] Glass-fiber reinforced composite is not classified under the category of number of layers. All the other options are classified under this category.
5. State true or false. The matrix phase controls the environmental resistance of the composites.
a) True
b) False
Answer
Answer: a [Reason:] The matrix phase controls the environmental resistance of the composites. Since Polymer Matrix Composites combine a resin system and reinforcing fibers, the properties of the resulting composite material will combine something of the properties of the resin on its own with that of the fibers on their own.
6. Select the incorrect statement from the following option.
a) Laminar composites consists of 2-D sheets that are stacked and subsequently cemented together
b) Sandwich panels consist of two stronger outer sheets separated by a layer of less dense core material
c) Core material should be heavy-weight and low corrosion resistance
d) The stiffness of the sandwich panel increases as the core thickness increases
Answer
Answer: c [Reason:] Core material should be light-weight and high corrosion resistance. All the other options are correct. Laminar composites consists of 2-D sheets that are stacked and subsequently cemented together. Sandwich panels consist of two stronger outer sheets separated by a layer of less dense core material and the stiffness of the sandwich panel increases as the core thickness increases.
7. One of the most popular type of core material used is
a) Metal foam
b) Honeycomb
c) Glass
d) Plastic
Answer
Answer: b [Reason:] One of the most popular type of core material used is honeycomb structure. Rest all options are not used widely as core material should be light-weight and high corrosion resistance.
8. The flexural stiffness of the sandwich panel is proportional to the _____________ of core thickness.
a) Square
b) Square root
c) Inverse
d) Cube
Answer
Answer: d [Reason:] The flexural stiffness of the sandwich panel is proportional to the cube of core thickness. It increases with the thickness of the core material.
9. Which of the following is not an application of sandwich panel?
a) Fabrication of wings of aircrafts
b) Design of ships, boat hulls
c) Conveyor belts
d) Fabrication of roofs, floors and walls of buildings
Answer
Answer: c [Reason:] Fabrication of wings of aircrafts, design of ships, boat hulls and fabrication of roofs, floors and walls of buildings are some of the applications of sandwich panel. Conveyor belts is not the application of sandwich panel.
10. When fibers are used as dispersed phase for the reinforcement of matrices, the resultant composites are known as
a) Glass-fiber reinforced
b) Carbon-fiber reinforced
c) Wood-fiber reinforced
d) Unidirectional-fiber reinforced
Answer
Answer: a [Reason:] When fibers are used as dispersed phase for the reinforcement of matrices, the resultant composites are known as glass-fiber reinforced. Glass-fiber reinforced composites should have low density, high impact resistance, high tensile strength and excellent chemical and corrosion resistance.
11. Which of the following is not a characteristic of glass-fiber reinforced composites?
a) Low density
b) Low impact resistance
c) High tensile strength
d) Excellent chemical and corrosion resistance
Answer
Answer: b [Reason:] Glass-fiber reinforced composites should have low density, high impact resistance, high tensile strength and excellent chemical and corrosion resistance.
12. Which of the following is an application of glass-fiber reinforced composites?
a) Adhesives
b) Conveyor belts
c) Design of ships
d) Automotive parts
Answer
Answer: d [Reason:] Automotive parts, storage tanks, plastic pipes etc are some of the applications of glass-fiber reinforced composites.
13. Which of the following is used as reinforcement in advanced polymer matrix composite?
a) Glass-fiber reinforced
b) Carbon-fiber reinforced
c) Wood-fiber reinforced
d) Unidirectional-fiber reinforced
Answer
Answer: b [Reason:] Carbon-fiber reinforced is used as reinforcement in advanced polymer matrix composite, which requires retention of desired properties.
14. Which of the following is not an advantage of composites?
a) Easy to manufacture and durable
b) Excellent thermal, mechanical and chemical properties
c) Heavy-weight and non-versatile
d) Economical and tailor made
Answer
Answer: c. [Reason:] Composites are light-weight and versatile. All the other options are correct. They are easy to manufacture and durable, have excellent thermal, mechanical and chemical properties and economical and tailor made.
15. State true or false. The principal applications of composites are in transportation industry, consumer products and industrial and scientific equipment.
a) True
b) False
Answer
Answer: a [Reason:] The principal applications of composites are in transportation industry, consumer products and industrial and scientific equipment. But composites can fail on the microscopic or macroscopic scale. Compression failures can occur at both the macro scale or at each individual reinforcing fiber in compression buckling. Tension failures can be net section failures of the part or degradation of the composite at a microscopic scale where one or more of the layers in the composite fail in tension of the matrix or failure of the bond between the matrix and fibers.
Set 5
1. Which type of polymer will be formed if the susbstituent group is –C6H5
a) Polythene
b) Polypropylene
c) Polystyrene
d) Polyvinyl chloride
Answer
Answer: c [Reason:] Polystyrene will be formed if the susbstituent group is –C6H5. It is a synthetic aromatic polymer made from the monomer styrene. Polystyrene can be solid or foamed.
2. Select the incorrect statement from the following option.
a) Addition polymerisation require the presence of double bond in monomer
b) No by-product is formed in addition polymerisation
c) In addition polymerisation, growth of chain is at one active centre
d) In addition polymerisation, polymer MW rises steadily throughout the reaction
Answer
Answer: d [Reason:] In addition polymerisation, high MW polymer is formed at once. All the other options are correct. Addition polymerisation require the presence of double bond in monomer and no by-product is formed. In addition polymerisation, growth of chain is at one active centre.
3. Select the incorrect statement from the following option.
a) Condensation polymerisation requires two reactive functional groups to be present at both ends of the monomer
b) No by-product is formed in condensation polymerisation
c) In condensation polymerisation, growth of chain occurs at minimum of the two active centres
d) In condensation polymerisation, polymer MW rises steadily throughout the reaction
Answer
Answer: b [Reason:] Generally a by-product is formed in condensation polymerisation. All the other options are correct.
Condensation polymerisation requires two reactive functional groups to be present at both ends of the monomer and growth of chain occurs at minimum of the two active centres. In condensation polymerisation, polymer MW rises steadily throughout the reaction.
4. The Ziegler Natta catalyst is formed between
a) Triethyl aluminium and titanium halide
b) Triethyl aluminium and silver halide
c) Triethyl aluminium and platinum halide
d) Triethyl aluminium and carbon halide
Answer
Answer: a [Reason:] The Ziegler Natta catalyst is formed between triethyl aluminium and titanium halide. It is named after Karl Ziegler and Giulio Natta, used in the synthesis of polymers of 1-alkenes (alpha-olefins).
5. The co-polymers having branched structures in which the monomer segments on the backbone and branches differ are called
a) Alternate
b) Graft
c) Random
d) Block
Answer
Answer: b [Reason:] The co-polymers having branched structures in which the monomer segments on the backbone and branches differ are called graft.
6. Which of the following act as initiator in free-radical polymerisation?
a) Grignard reagent
b) Lewis acids
c) Benzoyl peroxide
d) Potassium amide
Answer
Answer: c [Reason:] Benzoyl peroxide act as initiator in free-radical polymerisation. Benzoyl peroxide is used as an acne treatment, for bleaching flour, hair and teeth, for cross-linking polyester resins, and for many other purposes.
7. Which of the following act as catalyst in anionic polymerisation?
a) Grignard reagent
b) Lewis acids
c) Benzoyl peroxide
d) AIBN
Answer
Answer: a [Reason:] Grignard reagent act as catalyst in anionic polymerisation. The Grignard reaction is an organo-metallic chemical reaction in which alkyl, vinyl, or aryl-magnesium halides, CH3MgI (Grignard reagents) add to a carbonyl group in an aldehyde or ketone.
8. The temperature at which the ionic polymerisation is carried out is
a) 1000C
b) 500C
c) -1000C
d) 00C
Answer
Answer: d [Reason:] The temperature at which the ionic polymerisation is carried out is 00C. Ionic polymerization is a chain-growth polymerization in which active centers are ions or ion pairs.
9. State true or false. Radical polymerisation is not sensitive to changes in the polarity.
a) True
b) False
Answer
Answer: a [Reason:] Radical polymerisation is not sensitive to changes in the polarity. Free radical polymerization is a method of polymerization by which a polymer forms by the successive addition of free radical building blocks.
10. Which of the following monomer cannot be polymerised by radical polymerisation?
a) Butadiene
b) Isobutylene
c) Vinyl chloride
d) Acrylates
Answer
Answer: b [Reason:] Isobutylene monomer can be polymerised by cationic polymerisation. Butadiene, vinyl chloride and acrylates can be polymerised by radical polymerization.
11. The polymerisation in which propagating centers do not undergo either transfer or termination reactions is called
a) Addition polymerisation
b) Co-polymerisation
c) Living polymerisation
d) Dead polymerisation
Answer
Answer: c [Reason:] The polymerisation in which propagating centers do not undergo either transfer or termination reactions is called living polymerisation. Polymerization is a process of reacting monomer molecules together in a chemical reaction to form polymer chains or three-dimensional networks.
12. In esterification, the nucleophile is _________ and the leaving group is ____________.
a) Alcohol, ester
b) Ester, alcohol
c) Water, alcohol
d) Alcohol, water
Answer
Answer: d [Reason:] In esterification, the nucleophile is alcohol and the leaving group is water. Esterification is the general name for a chemical reaction in which two reactants (typically an alcohol and an acid) form an ester as the reaction product.
13. The reverse of esterification is
a) Hydrolysis
b) Condensation
c) Polymerisation
d) Centrifugation
Answer
Answer: a [Reason:] The reverse of esterification is hydrolysis. Hydrolysis is a reaction involving the breaking of a bond in a molecule using water. The reaction mainly occurs between an ion and water molecules and often changes the pH of a solution.
14. Which of the following is used for making cold drink bottles, magnetic recording tapes and housings for coffee machines?
a) Ethylene glycol
b) Polyethylene terephthalate
c) Hexamethylene diamine
d) Styrene butadiene
Answer
Answer: b [Reason:] Polyethylene terephthalate (PET) is used for making cold drink bottles, magnetic recording tapes and housings for coffee machines. PET consists of polymerized units of the monomer ethylene terephthalate, with repeating (C10H8O4) units and is commonly recycled.
15. State true or false. Terephthalic acid and ethylene glycol undergo polyesterification to form PET.
a) True
b) False
Answer
Answer: a [Reason:] Terephthalic acid and ethylene glycol undergo polyesterification to form PET. It is the most common thermoplastic polymer resin of the polyester family and is used in fibers for clothing, containers, etc.
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