Which one of the following is the result of applying a load to a wire below its modulus of elasticity on a load deflection diagram ? A. Fracture of the wire B. permanent deformationC. Spring back D. Increase in stiffness
A fluid having constant viscosity that does not depend upon the strain rate is said to be_______________? A. Viscoelastic B. Pseudoplastic C. PlasticD. Newtonian
Which of the following hardness test is a micro hardness test ? A. BrinnelB. Knoop C. Shore-A D. Rockwell
Which of the following properties of dental materials is time dependent_______________? A. Creep B. Resillience C. Elastic limit D. Ultimate strength
Flow of a material refers to_______________? A. Continued change of the material under a given load B. The consistency of material when mixing C. The homogencity of gypsum products D. Dimensional change of the material during settings
The ability of the base to resist occlusal forces and to support the restoration is affected by_______________? A. Compressive strength B. Tensile strength C. Young’s modulus D. Modulus of elasticity
The ability of an alloy to withstand mechanical stresses without permanent deformation is reflected by its______________? A. ResilienceB. Elastic limit / Elastic strain C. Hardness D. Fatigue resistance
Which of the following physical property can be used to estimate indirectly the proportional limit of gold alloys ? A. Vickers’s hardness number B. Knoop hardness numberC. Brinell hardness number D. Rockwell hardness number
Property of the material, which describes the resistance to abrasion, is_________________? A. Hardness B. Yield strength C. Modulus of elasticity D. None of the above
Ultimate tensile strength refers to_________________? A. Stress before rupture B. Stress after rupture C. Longitudinal compressive strength D. Horizontal compressive strength