Answer: no units.
- A no units
- B units of force
- C units of area
- D units of pressure
Correct answer: A. no units
Explanation: Being a ratio of like quantities, strain is dimensionless and unitless.
A typical stress-strain curve: the initial straight line (Hooke's Law region, slope = Young's modulus) ends at the elastic limit; beyond the yield point, deformation becomes permanent, peaking at the ultimate tensile strength before the wire finally fractures.
Concept context
Stress, strain, Hookes law, and the elastic moduli that describe how solids deform and recover under load.