Materials

The aim of materials science is to:

The valence electrons refer to the electrons on any orbit of an atom

A bond is a force that holds groups of two or more atoms together and makes them function as a unit.

Brittle fracture happens after extensive plastic deformations.

In a crystalline lattice, the coordination number is the number of nearest atoms for each basis:

Covalent bonds are primary chemical bonds involving:

Hook's law is a valid model for the stress strain relationship in the elastic strain ranges

Which of these statements is not true about hardness?

Creep measure the response of a material to repeated loadings

3D detects in a crystalline structure of a material always make them weaker

Ionic bonds involve metallic and nonmetallic elements

Defects can be introduced and/or removed during processing

Toughness is another term for the area below the stress strain curve in a tensile test

Compared to metals, polymers have larger bond energy, larger melting temperature and larger elastic moduli.

Poisson's ratio of a material is defined as the ratio of longitudinal strain to lateral strain

Ceramics are good thermal insulators due to their ionic bonds

The difference between Charpy or Izod tests is in the shape of the pendulum used.

Most metals have an ___________ structure

Anisotropic materials have no preterential directions with regards to mechanical properties

Melting temperature of a materials is inversely proportional to its coefficient of thermal expansion

In general, resilience has a higher value than toughness

Residual stress refers to a stress that develops after the load is removed

Some imperfections/defects in the crystalline structure of a material make them stronger

The units of hardness are kg/mm^2

Using engineering stress is intended to remove geometry from the loading conditions.

Modulus of rigidity is proportion with Young's modulus

Metals are ductile at all temperatures

Which of test is more appropriate for measuring the mechanical behavior of ceramics?

Covalent bonds are formed between

Electronegativity is the relative ability of an atom in a molecule to:

The repeated entity of a crystal structure is known as:

The dominant bond type in ceramics is:

In edge dislocation, a helical path is traced around the dislocation line

Materials engineering involves

Packing efficiency (APF) of a crystal structure is the ratio of:

A typical fatigue curve depicts the applied stress as a function of the time it requires to fail the materials under applied stress

The atomic packing factor is:

In a tensile test, which of the following does not affect the value of ultimate tensile strength:

In which of the following Bravais lattices, not all axial angles are right angles?

Which of the following can be the value of Poison's ratio for an engineering structure?

Which of test is more appropriate for measuring the mechanical behavior of metals?

Secondary bonds are also known as:

The dominant bond type in polymers is:

The coordination number of a crystaline solid is the:

Which of the following lattices has the lowest packing factor?

The dominant bond type in titanium is:

The four major material types are:

Which one of these 0D defects is specific to crystal structures with a basis that has an ionic bond?

At the point of necking, which of the following is false?

Which of the following can never be a reason for ductile failure?

At which point is necking observed?

Our role as engineers is to understand the application and specify the appropriate material based on multiple mechanical properties. Which of the following properties is not used in this process:

During a tensile test, which of the following is used to measure the elongation in the material?

Which of the following properties is impact strength indicative of?

Steels contain mainly iron and carbon. Under which of the following categories do they belong?