WBUT Question Papers EE
Control System Semester B Tech 5th Sem Dec 2008
- Choose the correct alternatives for any ten of the following: 10 x 1 = 10
i) The muxtmum overshoot, for an unity feedback system with open loop transfer
a) 014 b) 015 c) 016 d) 0-17. I— 11) A linear time Invariant system, when subjected to an unit step input, gives a response c (t) – te~*. The transfer function of the system is
Hi) The characteristic equation of a system issa + 3s + 2- 0. The system is
a) critically damped b) underdamped
a) increasing gain k b) decreasing gain k c) decreasing oscillating frequency d) increasing settling time.
|vlii) The settling time for a second order system responding to a step input with 5% overshoot is|
Find the transfer function for the block diagram shown below in figure-1. HI Cl
H2 H3 Pig. • 1
- Apply R-H criterion to determine the stability of the system of which characteristic equation Is given by : s5 +s4 +3ss +3s2 +6s+4-0.
- Draw the electrical analogous circuit using force-voltage analogy for the mechanical system shown In flgure-2.
^ <” ^ | M, | If x2
Find the transfer function of the system shown in flgure-3.
efficients corresponding to step, ramp & parabolic Inputs.
- Define error co
A unity feedback closed loop second order system has a transfer function g2 +0.6s + 9 Sltls excited by a step Input of 10 units. Find out Its steady state error. 3 * 2 GROUP -C ( Long Answer Type Questions ) Answer any three of the following questions.
- Sketch the root locus of the system with loop transfer function :
r,(s)H(s)m______ ———– . Show all relevant steps. G(s)H(s) s(s + 2)(s2+s + 1) (6/1ST . 7
- a) State and explain Nyquist stability criterion.
‘ b) The open loop transfer function of a unity negative feedback system Is given by
. G(s)- —————. Draw the Nyquist diagram & hence find out whether the s(s+l)(s+2)system is stable or not. 5+10
- a) Sketch the Bode plot of a unity negative feedback closed loop system of which
5 (s 2)
open loop transfer function is given by—————— —. Determine gam margin, phase margin, gain cross-over frequency & phase crossover frequency. b) b) Comment on the stability of the system.
- a) A second order system has the following transfer function : G (s)- . It is
s(s+6) connected with a unity feedback arrangement. Evaluate i) Wn, ii) |, iii) Wd, iv) tpand v) % Mp of the closed loop system. b) Find the steady state error of the system for input r(t)-l+t+—by static error co- efficient method.
- Write short notes on any three of the following :
- a) PED controller „
b) Servomotors c) Polar plots d) Speed control of D.C. motor using feedback.