Electrical Element

An electrical element is a component, which have at least two terminal. By terminal we mean, points through which current can pass through it . An element can be represented as, by a box. The direction of current is must to be represented along it . . Similarly the element , will have some voltage across it.

Different elements have different formulas for calculating current and voltage across them.

Circuit

By definition circuit mean, closed path. The below is an example of a circuit. Note that is it is important that circuit should be closed, or should be closed loop.

If the path is not closed, or have do not have a closed loop it does not fulfil the requirement of a circuit.

Electrical Circuit

An electrical circuit, is a combination of electrical components in a closed path, so they can provide us with required out put .

In the above figure, unless the switch is not closed, it can be called a complete circuit . .

It is important that circuit should be complete in order to current to flow. If the wires or any other component is not connected properly , the current will not flow .

In below example , we have two circuits. In first case the components are joined properly , so the bulb is glowing, how ever in second case , the wires are not connected properly, so the bulb does not glow

Figure 1 Current Flow and Bulb turns to yellow

Figure 2 Circuit not connected properly and hence current can not flow,

Node

A node is a point, where two or more than two terminals are connected

We may classify circuit elements in two categories, passive and active elements.

Passive Element: The element which receives energy (or absorbs energy) and then either converts it into heat (R) or stored it in an electric or magnetic field is called passive element.

Active Element: The elements that supply energy to the circuit is called active element.

Bilateral Element: Conduction of current in both directions in an element with same magnitude is termed as bilateral element.

Bilateral Element Example

Unilateral Element:

Conduction of current in one direction is termed as unilateral