CIRCUITS

Circuit: A circuit is a closed loop that electrons can travel in. A source of electricity, such as a battery, provides electrical energy in the circuit.  Unless the circuit is complete, that is, making a full circle back to the electrical source, no electrons will move.

circuit elements:The most commonly encountered linear one-ports are the inductor of inductance , the resistor of resistance  and capacitor of capacitance ; their schematic representations are shown on the figure.

series circuit: A series circuit is one that has more than one resistor, but only one path through which the electricity (electrons) flows. From one end of the cell (battery), the electrons move along one path with NO branches, through the resistors, to the other end of the cell. All the components in a series circuit are connected end-to-end.

A resistor in a circuit is anything that uses some of the power from the cell. In the example below, the resistors are the bulbs. In a series circuit, the components are arranged in a line, one after the other.

Take a look at the diagram below:
The schematic drawing is a better way to draw a series circuit.

Parallel circuits: In a parallel circuit, there is more than one resistor (bulb) and they are arranged on many paths. This means electricity (electrons) can travel from one end of the cell through many branches to the other end of the cell.

Look at the illustration below involving two resistors in a parallel circuit:

Mixed circuits: A third type of circuit involves the dual use of series and parallel connections in a circuit; such circuits are referred to as compound circuits or combination circuits. The circuit depicted at the right is an example of the use of both series and parallel connections within the same circuit.