Basic Concepts of Electrical Circuits!

Hi viewers, by reading this article, you'll be able to get a basic idea about electric circuit and circuit analysis. 



Introduction 

Electric Circuit - Mathematical model that approximate the behaviour on an actual electric system.

Current 

A direct current (dc) is a current that flows in one direction.
An alternative current (ac) is a current that reverse in direction periodically with time, normally sinusoidal (also triangular and square waves).

Voltage 

voltage is a potential difference between two points in a electric circuit. And it is measured in volts (V).

Electric voltage, Vab is always across the circuit element or between two points in a circuit.

Vab = Va - Vb

Vab > 0 :- The potential of a is higher than the potential of b.
Vab < 0 :- The potential of a is lower than the potential of b.

Example 1

Calculate the power supplied or absorbed by each element.



Solution

by applying P = Vi to every element in this circuit, (by using sign convention)



Circuit Elements

An active element is capable of generating energy while the passive element is not.

Examples of passive elements are resistors, capacitors and inductors. Typical active elements are generators and batteries.




An ideal independent source is an active element that provides a specified element or current that is completely independent of the circuit variable.

An ideal dependent source is an active element in which the source quantity is controlled by another voltage or current.

There are four possible types of dependent sources, namely:
1. A voltage-controlled voltage source (VCVS).
2. A current-controlled voltage source (CCVS).
3. A voltage-controlled current source (VCCS).
4. A current-controlled current source (CCCS).

Dependent sources are useful in modelling elements  such as transistors, operational amplifiers and integrated circuits.