A step is applied to a first-order process at t = 0. The output starts at 0 and settles at 100. At t = 1 s it reads 70. Find the time constant τ.
Step response worksheet with answers
A first-order system G(s) = 20/(s + 20) receives a step input of size 2 at t = 0, starting from rest. Find the final value y(∞) of the output.
A system has the transfer function G(s) = 40/(s² + 7s + 20) and receives a unit step input. Find the 2 % settling time ts of the step response, using ts ≈ 4/(ζωₙ).
A system has the transfer function G(s) = 99/(s² + 13s + 99) and receives a unit step input. The poles are s = σ ± jωd. Find the real part σ.
A second-order system without zeros must have a step response with 40 % overshoot. Find the damping ratio ζ.
A series RLC circuit with R = 179 Ω, L = 500 mH and C = 10 µF is connected to a 12 V step at t = 0. The capacitor is uncharged and no current flows before the step. Find the peak capacitor voltage vC,max.
Answer key
- 1. τ = 0.8306 s
- 2. y(∞) = 2
- 3. ts = 1.143 s
- 4. σ = −6.5
- 5. ζ = 0.28
- 6. vC,max = 15.04 V
Full step-by-step solutions: practise this topic on examproblems.com.