📖 Explanation
Comparing the given transfer functions with
s2+2ξωns+ωn2ωn2P=s2+2525⇒ξ=0
So, P is undamped. Q=s2+20s+3636⇒ξ=2×620=1.67 So, Q is overdamped. R=s2+12s+3636⇒ξ=2×612=1 So, R is critically damped. S=s2+7s+4949⇒ξ=2×77=0.5 So, S is underdamped.