The point where those electrons enter an electrical circuit is called the “source” of electrons. The point where the electrons leave an electrical circuit is called the “return” or “earth ground”. The exit point is called the “return” because electrons always end up at the source when they complete the path of an electrical circuit.
Linear Electric Circuit
In simple words, a linear circuit is an electric circuit in which circuit parameters (Resistance, inductance, capacitance, waveform, frequency etc) are constant. In other words, a circuit whose parameters are not changed with respect to Current and Voltage is called Linear Circuit.
Fundamentally, the word “linear” literally means “along with a straight line”. As the name tells everything, a linear circuit means linear characteristics in between Current and Voltage, which means, current flowing through a circuit is directly proportional to the applied Voltage.
If we increase the applied voltage, then the current flowing through the circuit will also increase, and vice versa. If we draw the circuit output characteristic curve in between Current and Voltage, it will look like a straight line (Diagonal) as shown in fig (1).
Refer to Ohm’s Law, where we recognize that:
“If the applied voltage increases, then Current also increases (where resistance remains same).”
But this is not always the case. That’s why we use P=VxI instead of V=IxR (in Transformer)
In other words,
In a linear circuit, the output response of the circuit is directly proportional to the input. Simple Explanation of the above statement is,
in an electric circuit, in which the applied sinusoidal voltage having frequency “f”, the output (Current through a component or Voltage between two points) of that circuit is also sinusoidal having frequency “f”.
Examples of Liner Circuits and Linear Elements
- Resistance and Resistive Circuit
- Inductor and Inductive Circuits
- Capacitor and Capacitive Circuits
Non Linear Circuit
A nonlinear circuit is an electric circuit whose parameters are varied with respect to Current and Voltage. In other words, an electric circuit in which circuit parameters (Resistance, inductance, capacitance, waveform, frequency etc) is not constant, is called Non Linear Circuit.
If we draw the circuit output characteristic curve in between Current and Voltage, it will look like a curved or bending line as shown in fig (2).
Examples of Non-Liner Electric Circuit and Non Linear Elements
- Diode
- Transistor
- Transformer
- Iron Core
- inductor (when the core is saturated)
- and any circuit composed exclusively of ideal Diode,
- Transistor
- Transformer
- and Iron Core inductor is called Non linear circuit.
Solving Linear and Nonlinear Circuits
Solving of a nonlinear circuit is a little bit complex then linear circuits. Linear circuit can be solved with simple techniques and scientific calculator. While solving Non linear circuits, a lot of data and information is required.
But nowadays, due to aggressive technological changes and Modernization, we can simulate and analyze, with output curves both linear and non linear circuits very easily with the help of circuit simulation tools like PSpice , MATLAB, Multisim etc.