Which metric measures the duration required for a decaying response to remain within a small band around the final value?

• A. Settle Time
• B. Overshoot
• C. Rise Time
• D. Peak Time

Answer: (A)

When a system responds to a change, we care not just about reaching the final value but about how long it stays close to that value as any transient dies away. The metric that measures this is settle time: the time elapsed from the moment the input is applied until the response enters a specified tolerance band around the final steady-state value and stays within that band thereafter. The tolerance band is a small percentage of the final value, so settle time tells you how quickly the system stabilizes.

Understanding the other metrics helps see why settle time fits this description. Overshoot is about how far the response goes beyond the final value at its peak, not about how long it takes to settle. Rise time concerns how fast the response climbs from a lower to a higher fraction of the final value, ignoring what happens after it first reaches that level. Peak time is simply the moment the first maximum occurs, which again doesn’t reflect how long the response remains near the final value. So settle time best captures the duration required for a decaying response to stay within a small band around the final value.