For a second order system ωn is natural frequency, ωd is frequency of damped oscillations and ζ is damping factor. Then

For a second order system ωn is natural frequency, ωd is frequency o

1.	For a second order system ωn is natural frequency, ωd is frequency of damped oscillations and ζ is damping factor. Then
A.	ωd = ωn ξ
B.	ωd = ωn (1 - ξ)²
C.	ωd = ωn (1 - ξ)^0.5
D.	ωd = ωn (1 - ξ²)^0.5
Answer» E.