Question

The breaking stress of a wire depends on:

• A. length of the wire
• B. radius of the wire
• C. material of the wire
• D. shape of the cross-section of the wire

Hint:

Distinguish between extrinsic and intrinsic properties. Extrinsic properties like mass, length, or breaking force depend on the amount or size of the object. Intrinsic properties like density, resistivity, or breaking stress depend only on the substance itself.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Breaking stress, also known as ultimate tensile strength (UTS), is a fundamental property of a material. It represents the maximum stress a material can withstand while being stretched or pulled before it fails or breaks.
Step 2: Detailed Explanation:
Stress is defined as the force applied per unit area (\(\sigma = F/A\)). The breaking stress is an intensive property, which means it depends on the internal structure and bonding of the material itself, not on the macroscopic dimensions of the sample.


Length and radius of the wire: These are geometric properties. While the breaking \textit{force} will depend on the radius (since \(F = \sigma \times A\)), the breaking \textit{stress} (force per area) is independent of these dimensions. A thick wire and a thin wire of the same material will break at the same stress.
Shape of the cross-section: Similar to length and radius, this is a geometric factor that does not affect the intrinsic strength of the material.
Material of the wire: The type of material (e.g., steel, copper, aluminum) determines the strength of the atomic bonds and the microstructure. These factors dictate the maximum stress the material can endure. Therefore, breaking stress is a characteristic property of the material.

Step 3: Final Answer:
The breaking stress of a wire is an intrinsic property that depends solely on the material of the wire.