Electrical Interview Questions: Control Systems 3

Electrical Interview Questions With Answers:

Electrical Question: What is Signal Flow Graph? 

Answer: A Signal Flow Graph is a diagram that represents a set of simultaneous linear algebraic equations. By taking Laplace transform the time domain differential equations governing a control system can be transferred to a set of algebraic equations in s-domain. The signal Flow graph of the system can be constructed using these equations.

Electrical Question: What is S-domain and its significance?

Answer: By taking Laplace transform for  differential equation in the time domain equations in S-domain can be obtained.    L{F(t)}=F(s)

S domain is used for solving the time domain differential equations easily by applying the Laplace for the differential equations.

Electrical Question: What are the basic properties of Signal Flow Graph?

Answer: The basic properties of the signal flow graph are:

• Signal Flow Graphs are applicable to linear systems
• It consists of nodes and branches. A node is a point representing a variable or signal. A branch indicates the functional dependence of one signal on another
• A node adds the signals of all incoming branches and transmits this sum to all outgoing branches
• Signals travel along branches only in a marked direction and is multiplied by the gain of the branch
• The algebraic equations must be in the form of cause and effect relationship

Electrical Question: What is mathematical model of a control system?

Related Topics Control Systems Interview Questions Answers 2 Control System Lab Viva Questions Closed Loop – Open Loop Control Systems Advantages Proportional Integral Derivative PID Control Control Systems Interview Questions Answers 5 Control Systems Interview Questions Answers Control Systems Interview Questions Answers 4 Thermal Power Plant Interview Questions 5

Answer: Control system is a collection of physical elements connected together to serve an objective. The output and input relations of various physical system are governed by differential equations. Mathematical model of a control system constitutes set of differential equations. The response of the output of the system can be studied by solving the differential equations for various input conditions.

Electrical Question: Explain Mechanical Translational System?

Answer: Model of mechanical translational system can be obtained by using three basic elements Mass, Spring and Dash-pot.

• Weight the mechanical system is represented by mass and is assumed to be concentrated at the center of body
• The elastic deformation of the body can be represented by the spring
• Friction existing in a mechanical system can be represented by dash-pot.