What are Linear and Non-linear Circuits and Its Differences?

The electrical devices are built with the help of the linear and nonlinear components. To understand the basic design of these devices, the fundamental understanding of linear circuit and non-linear circuit are necessary. In this article, we are discussing what is a linear and non-linear circuits with its differences, elements of the linear & nonlinear circuit and some of the examples are explained.

What are Linear and Non-linear Circuits?

Simply we can say that the linear circuit is an electric circuit and the parameters of this circuit are resistance, capacitance, inductance and etc are constant. Or we can say the parameters of the circuits are not changed with respect to the voltage and current is called the linear circuit.

Linear Circuit
Linear Circuit

The non-linear circuit is also an electric circuit and the parameters of this circuit differ with respect to the current and the voltage. Or in the electric circuit, the parameters like waveforms, resistance, inductance and etc are not constant is called as Non- linear circuit.

Non-Linear Circuit
Non-Linear Circuit

Difference Between the Linear and Non-Linear circuit

Generally, the word linear means a straight line which looks like diagonal and it tells about linear characteristics in between voltage and current. i.e  the current flow in the circuit is directly proportional to the voltage. If there is an increase in the voltage then the current flow in the circuit also increases and vice versa. The output characteristics of the linear circuit are between current and voltage of the figure is shown below.

Linear Circuit Characteristics
Linear Circuit Characteristics

In a linear circuit, the response of the output is directly proportional to the input. In the circuit, the applied sinusoidal having the frequency “f” and the output means the voltage between the two points is also having the sinusoidal frequency “f”.

In the non-linear circuit, the output characteristic is like a curve line which in between the voltage and current as shown in the following figure.


The other difference between the linear and nonlinear circuit is solving the circuit. In the linear circuits, the solving of the circuit is a simple by using a simple technique, using a calculator to solve and by comparing with the non-linear circuit the linear circuit is easy to solve

The solving of the non-linear circuits is complex than the linear circuit and there is a lot of data, information is required to solve the nonlinear circuits. Due to a lot of change in the technology, we can simulate and analyze the output curves of linear and nonlinear circuits with the help of the circuit simulation tools like Multisim, Matlab, and PSpice.

By using the equations of the linear and nonlinear we can find the difference between the linear circuit and nonlinear circuit. The equations are following.

Y = x + 2

Y = x2

The graph representation of the above two equations is shown in the following diagram. If any of the equation is a straight line represented in the graph, then it is a linear. If the equation is a curved line, then it is nonlinear.

Graph Reprasentation of Two Equations
Graph Representation of Two Equations

The piecewise linear is represented by the following equation and the x-y axis graph of the piecewise linear is also shown below. This equation is said to be as a nonlinear because we can’t write the equation as following.

Y = ax + b

Piece Wise Linear
Piece-Wise Linear

Elements of Linear and Non-Linear Circuit

In the non-linear circuit, the non-linear elements are an electrical element and it will not have any linear relationship between the current & voltage. The example of the nonlinear element is a diode and some of the nonlinear elements are not there in the electric circuit is called a linear circuit. Some other examples of the non-linear elements are transistors, vacuum tubes, other semiconductor devices, iron core inductors, and transformers.

If there is a presence of linear curves in the nonlinear curves, then it is called as the piece-wise-linear.

In the linear circuits, the linear element is also an electrical element and there will be a linear relationship between the voltage and current. The examples of the linear elements are resistor is the most common element, capacitor, and air core inductors.

Examples of Linear circuits of Linear Elements

The examples of linear circuits are resistance and resistive circuit, inductor and inductive circuit and capacitor and capacitive circuit.

Examples of Non-Linear Circuits of Nonlinear Elements

Some of the examples of nonlinear circuit of nonlinear elements are diode, transformer, iron core, inductor, transistor,

Applications of the Linear and Non-Linear circuits

  • The linear and nonlinear circuits are used in the electrical circuits
  • By using these circuit we can find voltage drop and current

This article will give the information about what are linear and nonlinear circuits and their differences. I hope by reading this topic you have gained some basic knowledge about the linear and nonlinear circuits. If you have any queries regarding this article or to implement electrical projects for engineering students, please feel free to comment in the below section. Here is the question for you, what are the linear and nonlinear circuits?


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