Source of Electrical Energy

There are two types of source of Electrical Energy. Ideal Voltage Source and Ideal Current source. But ideal voltage source and ideal current source doesn't exist practically, so we will discuss about practical source as well.

Voltage Source:

An ideal voltage source is two terminal element which maintains a terminal voltage v(t) regardless of the value of current through its terminal.

Internal Resistance of Ideal source is always Zero, which is not possible in practically.

In practical voltage source ,

The voltage across the terminal of source keep falling as the current through it increases because somewhere resistance is available in the path.

I am going to define differences between ideal and Practical Voltage source by figure given following:

Ideally internal resistance equal to zero but Practically internal resistance exist and is not equal to zero.

V-I Characteristics of Voltage source:

V-I characteristics of Ideal and Practical Voltage Source

Load or Internal Resistance in Voltage source:

Load resistance does not exist in ideal voltage source. it is always zero, but in practical voltage source

internal resistance or load resistance is Exist. we can define it by graph given below:

 

So it is clear that anything pure(Ideal) does not exist in the World.

Note: Ideally Voltage does not depends on current through its terminal, but practically it is not true. 

Current Source:

An ideal current source is a two terminal element which maintains a current i(t) flowing through its terminal regardless of the vale of the terminal voltage.

The internal Resistance of ideal current source is infinite.

In Practical Current source,

The current through the source decreases as the voltage across it increases. This behaviour can be explained by putting a resistance across the terminal of the source.

Practically somewhere internal resistance is exist.

Difference between ideal and practical current source:

V-I Characteristics of Current source:

Note: Ideally Current does not depend on terminal Voltage but Practical it is not true.

Basic Concept of Circuit Elements

Concept of Resistance | Ohm's Law

Next: Transformation of Circuit will be updated soon.....