GUJARAT TECHNOLOGICAL UNIVERSITY
BE - SEMESTER-V (NEW) EXAMINATION - WINTER 2018
--- Content provided by FirstRanker.com ---
Subject Code:2151908 Date:04/12/2018
Subject Name:Control Engineering
Time: 10:30 AM TO 01:00 PM Total Marks: 70
Instructions:
- Attempt all questions.
- Make suitable assumptions wherever necessary.
- Figures to the right indicate full marks.
--- Content provided by FirstRanker.com ---
MARKS
Q.1 (a) Draw a generalized closed loop feedback system with its components. 03
(b) Define transfer function. List important characteristics of transfer function. 04
--- Content provided by FirstRanker.com ---
(c) Explain Force-Voltage and Force-Current analogy. 07
Q.2 (a) Define: 03
- Control variable
- Manipulated Variable
- Process
--- Content provided by FirstRanker.com ---
(b) Simplify the block diagram shown in figure-1. 04
(c) In a liquid-level system assume that the outflow rate Q m³/sec through the 07 outflow valve is related to the head H m by Q = KvH = 0.01vH . Assume that when the inflow rate Q; is 0.015 m³/sec the head stays constant. At t =0 the inflow valve is closed and so there is no inflow for t >0. Find the time necessary to empty the tank to half the original head. The capacity C of the tank is 2 m³.
OR
(c) Simplify the block diagram shown in figure-2. Obtain the transfer function relating C(s) and R(s). 07
Q.3 (a) Explain the ramp input mathematically and graphically. 03
--- Content provided by FirstRanker.com ---
(b) For the following system: G(S) = K / (s(1 +s)(1 + 0.4s)) Find the value of k to limit the steady state error to 10% for input t. 04
(c) Draw the signal flow graph for the following set of algebraic equation: Y2 = aY1 — bY3; Y3 = eY2 + cY4 ; Y4 = bY1 — dY2. Hence find the gain. 07
OR
Q.3 (a) Discuss the effect of time constant on first order system response for unit step input. 03
(b) Give four points difference between Block diagram method and Signal Flow Graph method. 04
--- Content provided by FirstRanker.com ---
(c) Find the time response of a second order system for Unit step Response. 07
Q.4 (a) Enlist limitations of Routh’s stability criterion. 03
(b) Prove that steady state error for Step input is given as Ess = 1/(1+Kp), Kp = error constant 04
(c) Using Routh criterion, discuss about the stability for the system having characteristics equation is given as 3s7 +9s6 + 6s5+ 4s4 + 7s³ + 8s²+ 2s + 6 =0 07
OR
--- Content provided by FirstRanker.com ---
Q.4 (a) Write the draw backs of hydraulic system. 03
(b) Plot the root locus for a unity feedback system whose forward transfer function is G(S) = 1/(S(S+1)) 04
(c) For a unity feedback system having open loop transfer function G(S) = k / (s(s+4)(s+5)), using Routh criterion calculate the range of k for which the system is a) Stable b) Has its closed loop, poles more negative than -1. 07
Q.5 (a) Write three rules for drawing Signal flow graph. 03
(b) With the help of neat diagrams, explain how the direction control valves are classified. 04
--- Content provided by FirstRanker.com ---
(c) Draw the schematic diagram of Hydraulic PID controller. Explain its working and derive its transfer function. 07
OR
Q.5 (a) Explain FRL unit. 03
(b) Write the comparison between a Pneumatic system and Hydraulic system. 04
(c) Draw the schematic diagram of Pneumatic PI controller. Explain its working and derive its transfer function. 07
--- Content provided by FirstRanker.com ---
Figure-1
R(s) C(s)
G
H1
Figure-2
--- Content provided by FirstRanker.com ---
R(s) X(s) C(s)
G1 G2
--- Content provided by FirstRanker.com ---
This download link is referred from the post: GTU BE/B.Tech 2018 Winter Question Papers || Gujarat Technological University