National Dental Assisting Examining Board (NDAEB) Practice Exam

What term describes the amount of stress an alloy can withstand before fracture?

1. Compressive strength

2. Tensile strength

3. Elastic limit

4. Yield strength

The correct answer is: Tensile strength

The term that describes the amount of stress an alloy can withstand before fracture is tensile strength. Tensile strength is specifically the measure of the maximum amount of tensile (pulling) stress that a material can endure before failure or fracture occurs. It is a critical property in materials science, as it indicates how much load a material can handle while stretched or pulled before losing its integrity. In contrast, compressive strength pertains to the maximum load that a material can withstand while being compressed, which is not directly relevant in this context since the question specifically refers to stress under tensile conditions. The elastic limit refers to the maximum stress that a material can withstand without permanent deformation, which does not directly correlate to the point of fracture. Yield strength is the amount of stress at which a material begins to deform plastically; while it is important, it occurs before fracture and does not represent the ultimate point of structural failure under tension. Thus, tensile strength is the most accurate term for the maximum stress an alloy can endure before breaking.