(SEM V) THEORY EXAMINATION 2017-18 CONTROL SYSTEM

CONTROL SYSTEM (NEE-503)

B.Tech | Semester V | Section-wise Important Questions & Notes

SECTION A – Short Answer (2 × 10 = 20 Marks)

This section focuses on basic theory, definitions, and small numericals. Answers should be brief but clear.

Important Questions

Major types of control systems with examples

Definition of P, PI, and PID controllers

Stability test of a system using characteristic equation

Derivation of transfer function from a given network

Polar plot of a simple transfer function and its properties

Open loop vs Closed loop control system (block diagram + explanation)

Expression of error E(s) for a unity feedback system

Definition of signal flow graph

Importance of negative feedback

Purpose of block diagram reduction rules

Key Notes

Open loop → simple but less accurate

Closed loop → accurate, stable, less sensitive to disturbances

PID controllers improve steady-state and transient response

Negative feedback improves stability and bandwidth

SECTION B – Analytical & Numerical (Attempt Any 3, 10 × 3 = 30)

This section is very important and often repeated in exams.

Important Questions

Find system type, error constants, and steady-state error for step, ramp, and parabolic inputs

Check controllability and observability using state-space matrices

Draw root locus for a unity feedback system

Short notes on:

Centroid

Breakaway points                  Steady-state error

Determine system type and error for a given unity feedback transfer function

Key Notes

System type depends on number of poles at origin       Error constants: Kp, Kv, Ka

Root locus shows closed-loop pole movement

Controllability & observability depend on matrix rank

 SECTION C – State Space Concepts (10 Marks)

 Important Questions

Convert a differential equation into state-space representation

Define state and state variables                                  Advantages of state-space analysis

Key Notes

State variables represent system memory                    State-space method works well for MIMO systems

Time-domain based approach