Classification of Electrical Networks
- Active network contains at least one voltage source or current source
- Passive network does not contain an active source
- Active elements can inject power, provide power gain, and control current flow
- Passive networks consist of resistors and capacitors
- Active networks are generally nonlinear and require complex design and analysis tools
- By passivity, active network contains electromotive force sources like batteries or generators
- Passive network does not contain any electromotive force sources
- Passive networks consist of resistors and capacitors
- Active elements can inject power, provide power gain, and control current flow
- Passive networks are generally linear, but there are exceptions
- By linearity, linear network obeys the principle of superposition
- Nonlinear network does not obey the principle of superposition
- Passive networks are generally linear, but there are exceptions
- Inductor with an iron core can exhibit nonlinear behavior
- Linear networks are easily analyzed using frequency domain methods
- By lumpiness, discrete passive components are called lumped elements
- Lumped elements assume resistance, capacitance, and inductance are located at one place
- Lumped-element circuits are designed based on the lumped-element model
- At high frequencies or for long circuits, the lumped assumption no longer holds
- Distributed-element circuits are designed for such cases

Classification of Sources
- Sources can be independent or dependent
- Independent sources maintain constant voltage or current regardless of the circuit
- Dependent sources deliver power or voltage or current depending on the circuit element
- Ideal independent sources have constant or sinusoidal values
- Dependent sources rely on specific elements in the circuit for their operation

Applying Electrical Laws
- Kirchhoff's current law states that the sum of currents entering a node equals the sum of currents leaving the node
- Kirchhoff's voltage law states that the sum of potential differences around a loop is zero
- Ohm's law relates voltage, resistance, and current in a resistor
- Norton's theorem states that any network can be replaced by an ideal current source in parallel with a resistor
- Thevenin's theorem states that any network can be replaced by a voltage source in series with a resistor

Design Methods
- Electrical circuits can be designed using linear network analysis
- Components and elements play a crucial role in circuit design
- Series and parallel circuits are fundamental building blocks
- Impedance transforms help analyze circuits with complex impedances
- Network theorems like Norton's and Thevenin's aid in circuit simplification

Network Simulation Software
- Complex circuits can be analyzed numerically with software like SPICE or GNUCAP
- Symbolic software like SapWin can be used for circuit analysis
- Steady state solution is found to determine operating points of each circuit element
- Small signal analysis linearizes non-linear elements around their operating points
- Linear circuit matrix can be solved using Gaussian elimination