BE/B Eng Bachelor of Engineering Materials Engineering 1

Question 1

What is the crystal structure of most common metals at room temperature called?

Accepted Answer

Face-Centered Cubic (FCC), Body-Centered Cubic (BCC), or Hexagonal Close-Packed (HCP)

Answer

Simple cubic

Answer

Diamond cubic

Answer

Amorphous

Question 2

What is the glass transition temperature (Tg) of a polymer?

Accepted Answer

The temperature below which a polymer transitions from a rubbery to a glassy, brittle state

Answer

The temperature at which a polymer melts completely

Answer

The temperature at which a polymer begins to oxidize

Answer

The temperature at which a polymer crosslinks

Question 3

What is the purpose of alloying in metals?

Accepted Answer

To improve mechanical properties such as strength, hardness, or corrosion resistance

Answer

To reduce the melting point to near room temperature

Answer

To make metals transparent

Answer

To eliminate electrical conductivity

Question 4

What does a phase diagram for a binary alloy system show?

Accepted Answer

The equilibrium phases present at various temperatures and compositions

Answer

The mechanical strength as a function of temperature

Answer

The electrical conductivity versus composition

Answer

The diffusion rate of atoms in the alloy

Question 5

What is the Vickers Hardness Test used to measure?

Accepted Answer

A material's resistance to permanent deformation by indentation

Answer

A material's tensile strength

Answer

A material's resistance to fracture

Answer

A material's thermal conductivity

Question 6

What is the difference between thermoplastic and thermoset polymers?

Accepted Answer

Thermoplastics can be remelted and reshaped; thermosets permanently harden after curing

Answer

Thermosets are always softer than thermoplastics

Answer

Thermoplastics cannot be recycled under any conditions

Answer

Thermosets have lower melting points than thermoplastics