MCQ Practice Question Control SystemsTime Response A standard second-order system has ζ=0.6 and ωn=5 rad/s. Its damped natural frequency ωd is? A2 rad/s B3 rad/s C4 rad/s D5 rad/s Show AnswerHide AnswerReport an error Correct Answer: C. 4 rad/s Explanation: ωd=ωn√(1-ζ²)=5√(1-0.36)=5×0.8=4 rad/s.Reference: Standard control systems: time response