Spring terminology:\nThe load (force) required to produce a unit deflection of a spring is termed as what?

Introduction / Context:
Springs are characterized by how much they deflect under load. The direct proportionality constant between load and deflection in the elastic range is the spring stiffness, a critical parameter for designing suspensions, valves, and vibration isolators.

Given Data / Assumptions:

• Small deflections in the elastic range (Hooke’s law holds).
• Deflection measured along the spring’s working direction.
• Material and geometry fixed.

Concept / Approach:
For linear springs, F = k * x, where F is load, x is deflection, and k is spring stiffness (spring rate). Therefore, the load required for unit deflection is simply k. Other listed terms are stiffness-related but apply to beams or torsional members, not directly to overall spring response in translation.

Step-by-Step Solution:

Verification / Alternative check:
Dimensionally, k has units of force per unit displacement (e.g., N/mm), matching “load per unit deflection.”

Why Other Options Are Wrong:

• Flexural rigidity (E * I) applies to beam bending stiffness, not directly to a spring’s axial rate.
• Torsional rigidity (G * J) is a torsional stiffness measure of a shaft or rod.
• Young’s modulus is a material constant, not the overall element stiffness.

Common Pitfalls:
Confusing material modulus with system stiffness; stiffness depends on geometry and boundary conditions in addition to material properties.

Final Answer:
Spring stiffness