1) For a second order system, damping ratio , 0< <1 , the roots of the characteristic polynomial are
a) Real, but not equal
b) Real and equal
c) Complex conjugates
d) Imaginary
2) For a second order control system with the closed loop transfer function
T(s) = , the settling time for 2 percent band is (In seconds)
a) 1.5
b)2
c) 3
d) 4
3) Consider a system with transfer function G(s)= . Its damping ratio will be 0.5 when the value of K is
a) 2/6
b) 3
c) 1/6
d) 6
4) A unity feedback control system has the open loop transfer function
G(s)= . If the input to the system is a unit ramp, the steady state error will be
a) 0
b) 0.5
c) 2
d) Infinity
5) A causal system having the transfer function G(s) = is excited with 10 u(t). The time at which the output reaches 99% of its steady state value is
a) 2.7 seconds
b) 2.5 seconds
c) 2.3 seconds
d) 2.1 seconds
6) A ramp input applied to an unity feedback system results in 5% steady state error. The type number and zero frequency gain of the system are
a) 1 and 20
b) 0 and 20
c) 0 and 1/20
d) 1 and 1/20