5. EFFECTS OF ELECTRIC CURRENT

5.1. Heat.
The energy that an electric current produces as heat is called the Joule Effect.
It is expressed by the following formula:
                                                E = I^2 x R x t

5.2. Light.
Incandescent bulbs.
When an electric current passes through the metallic filament of a lightbulbs, it produces light. This phenomenon is called incandescence.

Fluorescent tubes.
Inside a fluorescent tube, there is a metallic filament, normally of tungsten. There is also an inert gas, such as argon, and a small amount of mercury.

Light-emitting diodes (LED)
A light-emitting diode (LED) has layers of semiconductor materials.

5.3. Electromagnetic effects.
In this experiment, the electric circuit has created a magnetic field. This effect can be used to produce movement.

5.4. Sound.
We can transform electric current into sound by using electromechanical devices, such as bells and buzzers. Some of these devices are based on the piezoelectric effect.