Polymers in Engineering: Properties, Applications, and Exam Prep

Question 1

What type of chemical bond primarily forms the backbone of a polymer chain?

Accepted Answer

Covalent bond

Answer

Ionic bond

Answer

Hydrogen bond

Answer

Van der Waals force

Question 2

What is the term for the temperature at which a polymer transitions from a glassy to a rubbery state?

Accepted Answer

Glass transition temperature

Answer

Crystallization temperature

Answer

Melting temperature

Answer

Annealing temperature

Question 3

What is the main difference between a thermoplastic and a thermosetting polymer?

Accepted Answer

Thermoplastics can repeatedly soften upon heating and harden upon cooling, while thermosets cannot.

Answer

Thermosets are stronger than thermoplastics.

Answer

Thermoplastics are more resistant to heat than thermosets.

Answer

Thermosets are more expensive than thermoplastics.

Question 4

What is the purpose of a plasticizer in a polymer formulation?

Accepted Answer

To reduce the polymer's stiffness and increase its flexibility.

Answer

To enhance the polymer's strength.

Answer

To improve the polymer's weather resistance.

Answer

To increase the polymer's thermal stability.

Question 5

Which of the following techniques is primarily used to determine the average molecular weight of polymers?

Accepted Answer

Gel permeation chromatography

Answer

X-ray diffraction

Answer

Differential scanning calorimetry

Answer

Atomic force microscopy

Question 6

What is the significance of the Poisson's ratio for polymers?

Accepted Answer

It indicates the material's tendency to contract in one direction when stretched in another.

Answer

It is a measure of the material's stiffness.

Answer

It is a measure of the material's strength.

Answer

It is a measure of the material's toughness.

Question 7

What is the key difference between thermoplastics and thermosetting polymers?

Accepted Answer

Thermoplastics can be repeatedly melted and reshaped, while thermosetting polymers cannot.

Answer

Thermosetting polymers are stronger than thermoplastics.

Answer

Thermoplastics are more resistant to chemicals than thermosetting polymers.

Answer

Thermosetting polymers have higher melting points than thermoplastics.

Question 8

Which technique is commonly used to determine the molecular weight of a polymer?

Accepted Answer

Gel permeation chromatography

Answer

Atomic force microscopy

Answer

Scanning electron microscopy

Answer

X-ray diffraction

Question 9

Which polymer is known for its high heat resistance and electrical insulation properties?

Accepted Answer

Polytetrafluoroethylene

Answer

Polystyrene

Answer

Polyvinyl chloride

Answer

Polyethylene terephthalate

Question 10

Which monomer is the building block for polypropylene?

Accepted Answer

Propylene

Answer

Ethylene

Answer

Styrene

Answer

Vinyl chloride

Question 11

What is a key advantage of using polymer blends in engineering applications?

Accepted Answer

They often offer improved mechanical properties.

Answer

They are always cheaper than using individual polymers.

Answer

They are easy to process with standard equipment.

Question 12

Which of the following is definitively NOT a type of polymer?

Accepted Answer

Metal

Answer

Thermoplastic

Answer

Thermoset

Answer

Elastomer

Question 13

Which property is a defining characteristic of thermoplastic polymers?

Accepted Answer

Ability to be repeatedly melted and reshaped without substantial degradation

Answer

High strength-to-weight ratio

Answer

Electrical conductivity

Answer

Resistance to elevated temperatures

Question 14

Which of the following is a primary application of elastomers?

Accepted Answer

Tires

Answer

Structural components in buildings

Answer

Biomedical devices

Answer

Electrical insulation

Question 15

Which intermolecular force is primarily responsible for the cohesion between polymer chains?

Accepted Answer

Van der Waals forces

Answer

Ionic bonds

Answer

Covalent bonds

Answer

Hydrogen bonds

Question 16

What is the scientific term for the process of forming a polymer from its constituent monomers?

Accepted Answer

Polymerization

Answer

Curing

Answer

Condensation

Answer

Vulcanization

Question 17

Which of the following polymers exhibits biodegradability?

Accepted Answer

Polylactic acid (PLA)

Answer

Polystyrene (PS)

Answer

Polyethylene (PE)

Question 18

What is the primary advantage of incorporating fibers into polymers to create fiber-reinforced polymers?

Accepted Answer

Substantial improvement in strength-to-weight ratio

Answer

Improved transparency

Answer

Enhanced electrical conductivity

Answer

Increased biodegradability

Question 19

Which of the following is NOT a method commonly used to characterize the mechanical properties of polymers?

Accepted Answer

Electrical conductivity test

Answer

Tensile test

Answer

Impact test

Answer

Compression test

Question 20

What is the significance of the glass transition temperature (Tg) in the context of polymers?

Accepted Answer

It marks the transition from a glassy, rigid state to a rubbery, flexible state

Answer

It indicates the tensile strength

Answer

It represents the melting point