Effects of electric current.

In conductive materials, the movement of electrons have useful applications.


HEAT.

When the movement of electrons is both slow and disorderly, and they often collide, the temperature increases of the cable itself.
The energy as heat produces by an electric current is called the Joule Effect, that is expressed as: E= I (square) x R x t.
The energy consumed by radiators and heaters is converted into heat.

LIGHT.

There are various forms that electricity can be used to produced light:

Incandescent bulbs.

We can produce light when in a metallic filament of a light bulb  passes an electric current. It is called incandescence.

Fluorescent tubes.

They have a metallic filament made of tungsten, and it has inside too and inert gas and a small amount of mercury. When an electric current passes through it , electrons are emitted into the inert gas. This react produces ultraviolet gas , and after phosphor coating inside the tbe transforms it into visible light.
But this type of tubes contain toxic substances, such as mercury.

Light-emitting diodes (LED)

A light-emitting diodes has layers of semiconductor materials, and it can have a n-type layer with negative charge and a p-type layer with ot enough electrons. When electricity is applied to the LED, this whole electrons cross into the active plaer, whre they produce particles of light.

INCANDESCENT BULB                FLUORESCENT  TUBE           LIGHT EMITING DIODE (LED)

ELECTROMAGNETIC EFFECTS.

The discovery maked by Michael Faraday tell us that electricity could be generated by using a magnet and an electrical conductor. It allows us to build dynamos and alternators. Magnetic fields are created thanks to the electric current produced by electromagnets.

SOUND.

Bells and buzzers help us to transform an electric current into sound. These devices are based on the piezoelectric effect that changes their shapes when we applied electricity to them.

BELL, BUZZER.

MICHAEL FARADAY