Creep vs Fatigue: which statement correctly contrasts them?

• A. Creep is constant, fatigue fluctuating
• B. Creep is fluctuating, fatigue constant
• C. Both are the same
• D. Creep occurs at high temperature only

Answer: (A)

Creep and fatigue respond to loading in different time patterns. Creep is the slow, time-dependent deformation under a constant load, typically enhanced by higher temperature. Fatigue is failure that results from repeated or fluctuating (cyclic) stresses, even if each load is below the material’s ultimate strength. So the statement that best contrasts them is that creep involves a constant load, while fatigue involves fluctuating or cyclic loading. The other ideas mix up these distinctions: creep isn’t about fluctuating stress, fatigue isn’t a constant-load phenomenon, and creep isn’t strictly limited to high temperature (it speeds up with temperature but can occur at lower temperatures given sufficient time).