Topic 4.1

Question 1

Electrical resistivity

Answer 1

The measure of a material’s ability to conduct or resist electricity

Question 2

Thermal conductivity

Answer 2

A measure of how fast heat is conducted through a slab of material with a given temperature difference

Question 3

Thermal expansion

Answer 3

A measure of the degree of increase in dimensions of a material when it is heated

Question 4

Hardness

Answer 4

The resistance a material offers to penetration or scratching

Question 5

Tensile Strength

Answer 5

The ability of a material to withstand pulling forces

Question 6

Compressive strength

Answer 6

The ability of a material to withstand squashing forces

Question 7

Stiffness

Answer 7

The resistance of an elastic body to deflection by an applied force (maintaining shape)

Question 8

Toughness

Answer 8

The ability of a material to resist the propagation of cracks

Question 9

Brittle

Answer 9

Low toughness; breaking into numerous sharp shards

Question 10

Ductility

Answer 10

The ability of a material to be drawn or extruded into a wire or other extended shape

Question 11

Malleability

Answer 11

The ability of a material to be shaped plastically

Question 12

Elasticity

Answer 12

The ability of a material to reach its original shape when it is bent

Question 13

Plasticity

Answer 13

The material deforms plastically and does not return to its original position

Question 14

Stress in the member

Answer 14

The load on a structural member divided by its cross-sectional area

Question 15

Strain

Answer 15

A measure of the relative change of shape it undergoes when subjected to a load

Question 16

Young’s Modulus

Answer 16

Measure of stiffness of a given material (Stress:Strain)

Question 17

Piezoelectricity

Answer 17

Piezoelectric materials give off a small electrical discharge when deformed

Question 18

Shape Memory Alloys

Answer 18

Metals that exhibit pseudo-elasticity and shape memory effect due to rearrangement of the molecules in the material.

Question 19

Shape memory effect

Answer 19

Allows severe deformation of a material, which can then be returned to its original shape by heating it

Question 20

Pseudo-elasticity

Answer 20

The ability of a shape memory alloy to rearrange its molecules when there’s a load applied to it and reverses back to its original shape when load is decreased without changing its temperature.

Question 21

Paramagnetism

Answer 21

A form of magnetism whereby certain materials are weakly attracted by an externally applied magnetic field.

Question 22

Photochromicity

Answer 22

The ability of a material to change its colour when exposed to light.

Question 23

Magneto-rheostatic material

Answer 23

A fluid that can undergo dramatic changes in its viscosity when exposed to a magnetic field and the effect is reversed when the field is removed.

Question 24

Electro-rheostatic material

Answer 24

A fluid that can undergo dramatic changes in its viscosity when exposed to an electric field and the effect is reversed when the field is removed.

Question 25

Viscosity

Answer 25

Thickness of a fluid

Question 26

Thermoelectricity

Answer 26

Electricity produced directly from heat.