Question

For a second order system, damping ratio $\left(\xi \right)$, is $0<\xi <1$, then the roots of the characteristic polynomial are

• A. real but not equal
• B. real and equal
• C. complex conjugates
• D. imaginary

Answer 1

The correct option is C complex conjugates

$\xi <1$
For underdamped system, roots or poles are:
$s=-\xi {\omega }_n\pm j{\omega }_n\sqrt{1-{\xi }^2}$