Parallel circuit

If identical batteries are connected in parallel, the voltage of the circuit will not increase. However, the total consumption of energy will be shared between the batteries, so each one will last longer.

Series circuit

Two or more elements form a series circuit when the output of one element provides the input for the next element.

To calcule the total resistance of a circuit, we add the resitance valvues of each load:

                                                          R=R1+R2+R3+...

One example of this type of connection would be a series of generators. The totral resistance woulbe the sum of all the resistance values.

Electrical energy and power

Electrical energy

If an electric current flows at a  particular tension for a certain amount of time, we can calculate the energy that is consumed: E=V x I x t

In the SI, this electrical energy is measured in joules (J)

Electrical power

The elctric power of a load is the amount of energy that it can transform over a certain amount of time. Electric power is measured in watts (W) or kilowatts (kW).

Electrical resistance: Ohm's Law

The resistance of a material is equal to the voltage divided by the intensity of the electric current which travels throught the material. This ratio, which is called Ohm's Law, can be expressed as follows:

                                                                  R=V/I

                                                           
Ohm's Law has two forms:

                                                       V= RxI       and         I=V/R

Measuring electric energy

Electric current is the charge or number of electrons that flow throught the coss section of a conductor every second. We can express this mathematically as foollow:
                                                                         
                                                                      I= Q/t

Elctric current is measured in amperes or amps in the international System or SI.

Voltage or potential energy

The amount of energy that a generator (electrochemical cell or battery) can transfer to electrons depends on its voltage or electric tension. This is measured in volts.

Diagrams and symbols

Electric circuit

An electric circuit is a pathway for the flow of electrons.

Electric current is a continuous flow of electrons throught a circuit.

Parts of an electric circuit

Electric circuits consist of various parts:

Generators: provides the energy that electrons need in order to move.

Loads: are devices that transform electrical energy into other types of energy that we can use.

Switching devices: are used to direct and interrupt the flow of electric current.