A step is applied to a first-order process at t = 0. The output starts at 0 and settles at 8. At t = 2 s it reads 4.8. Find the time constant τ.
Step response worksheet with answers
An uncharged capacitor C = 100 µF is charged from a 24 V step source through a resistor R = 100 kΩ. Find the 10–90 % rise time tr of the capacitor voltage, in ms.
A system has the transfer function G(s) = 18/(s² + 4s + 36) and receives a unit step input. Find the peak time tp of the step response.
A system has the transfer function G(s) = 47/(s² + 3s + 47) and receives a unit step input. The poles are s = σ ± jωd. Find the real part σ.
A unity negative feedback loop has G(s) = 235/(s(s + 10)). Find the 2 % settling time ts of the closed-loop step response, using ts ≈ 4/(ζωₙ).
The step response of a second-order system without zeros shows 10 % overshoot, and the first peak occurs at t = 2 s. Find the natural frequency ωn.
Answer key
- 1. τ = 2.183 s
- 2. tr = 21972 ms
- 3. tp = 0.5554 s
- 4. σ = −1.5
- 5. ts = 0.8 s
- 6. ωn = 1.948 rad/s
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