What are state variables give an example?

What are state variables give an example?

In thermodynamics, a state variable is an independent variable of a state function like internal energy, enthalpy, and entropy. Examples include temperature, pressure, and volume. Heat and work are not state functions, but process functions.

Are state functions and state variables same?

A state function is a relationship between thermodynamic quantities—what it means is that if you have N thermodynamic variables that describe the system that you are interested in and you have a state function, then you can specify N − 1 of the variables and the other is determined by the state function.

Which is the best description of a state variable?

•State Variables –Set of variables of smallest possible size that together with any input to the system is sufficient to determine the future behavior (I.e., output) of the system. –Each state variable has “memory” E.g., voltage in capacitor –Each state variable has an “initial condition” E.g., its state at time t 0

Which is the state variable of an inductor?

In any electrical circuit, the number of state variables are equal to the number of storage elements, which are inductors and capacitors. The state variable for an inductor is the current through the inductor, while that for a capacitor is the voltage across the capacitor.

Which is a state variable in a mechanical system?

In mechanical systems, the position coordinates and velocities of mechanical parts are typical state variables; knowing these, it is possible to determine the future state of the objects in the system. In thermodynamics, a state variable is also called a state function.

How are state variables used in control engineering?

In control engineering and other areas of science and engineering, state variables are used to represent the states of a general system. The set of possible combinations of state variable values is called the state space of the system.