# Control System Interview Questions and Answers

### Control System Interview Questions and Answers

[1] What is meant by system?
A system is defined as any physical object comprises of various components which are inter connected with each other by some characteristics.
Example: Automobile

[2] What is meant by control system?
It is possible to vary any of the characteristics of a components in a system according to the requirements, then the system is called a controllable system or control system.
For example consider an automobile, where the speed can be varied by adjusting the accelerator to the desired level.

[4] What are the major types of control system?
The major types of control systems are

1. Open loop control system
2. Closed loop control system

[5] What is time invariant system?
If system's output characteristics do not change with time, then it is called as time invariant system.
A linear time invariant system can be represented by constant co-efficient differential equations.

[6] What is meant by analogous systems?
The system for which the differential equations have similar form are known as analogous system.

[7] What are the advantages and disadvantages of open loop control systems?
Advantages:
(i) Open loop control is much simpler and less expensive
(ii) No sensors are needed to control the variables.

Disadvantages:
(i) No accurate control
(ii) There is no compensation for any disturbances entering the system since it has fixed input.

[8] What are the advantages and disadvantages of closed loop control system?
Advantages:
(i) More accurate control
(ii) It compensates for disturbances
(iii) Desired response can be obtained by appropriate design

Disadvantages:
(i) More complex and expensive
(ii) Reduces the gain of the system
(iii) If the closed loop system is not properly designed, the feedback may lead to an oscillatory system

[9] What is an order of a system?
The order of the differential equation governing the system is called as the order of a system.
From the transfer function of the given system, we can obtain the order of the system.