PART A(10*2=20)
Answer All Questions:
1.What are the advantages of the closed loop control system?
2.Why negative feedback is invariably preferred in a closed loop system?
3.Write the Mason’s gain formula of signal flow graph.
4.The closed loop transfer function of a second order system is given by 400/s2+2s+400.Determine the damping ratio and natural frequency of oscillation.
5.Write the necessary and sufficient condition for stability in Routh stability criterion.
6.Define sampling theorem.
7.How will you find root locus on real axis?
8. Why derivative controller is not used in control systems?
9.Define phase margin and gain margin.

10. What is centroid?