The document discusses different types of voltage and current sources. It defines an ideal voltage source as maintaining a fixed voltage drop across its terminals, while a current source delivers or absorbs current independently of voltage. Dependent sources have their voltage or current values vary based on another variable, and can be classified as voltage-controlled voltage sources, voltage-controlled current sources, current-controlled current sources, or current-controlled voltage sources. Independent sources maintain voltages or currents unaffected by other quantities.

2. An ideal voltage source is a two-terminal device that
maintains a fixed voltage drop across its terminals. It is
often used as a mathematical abstraction that
simplifies the analysis of real electric circuits
Ideal Voltage Source

3. A current source is an electronic circuit that delivers or
absorbs an electric current which is independent of the
voltage across it.
A current source is the dual of a voltage source.

5. Some voltage (current) sources have their voltage
(current) values varying with some other variables.
They are called dependent voltage (current) sources
or controlled voltage (current) sources.

6. 1.Voltage-controlled voltage source:
The source delivers the voltage as per the voltage of the
dependent element.
V={f_{a}}({v_{x}})
Dependent sources can be classified as follows:

7. 2.Voltage-controlled current source:
The source delivers the current as per the voltage of the
dependent element.
I={f_{b}}({v_{x}})
3.Current-controlled current source:
The source delivers the current as per the current of the
dependent element.
I={f_{c}}({i_{x}})

8. 4.Current-controlled voltage source:
The source delivers the voltage as per the current of the
dependent element.
V={f_{d}}({i_{x}})

9. An independent voltage source maintains a
voltage(fixed or varying with time) which is not
affected by any other quantity. Similarly
an independent current source maintains a current
(fixed or time-varying) which is unaffected by any
other quantity.