ENGINEERING – WORKING PRINCIPLE OF A LIGHT BULB

Hello everyone, welcome to another engineering class on the working principle of an electric bulb. The electric bulb is the most common house hold appliance in the world today, even though it has been modified in different form and style, but they all still have a simple working principle which follows the law of conservation of energy.

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the law of conservation of energy simply states that energy cannot be created non destroyed, it can only be transferred from one form to another. This is a law that governs the actions of everything on earth.
In the case of an electric bulb, energy is converted from Electric energy to light energy. The electric bulb consist of 3 major materials, the filaments, the glass bulb and the inert gas, others are the lead and base.

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The filament is made up of an element known as tungsten which has a very high melting point, thus it also has a very high resistance. When electric current is passed through the filament, it causes the atoms to move rapidly which results in increase in temperature and heat generation, when this happens, the tungsten begins to glow Just like when you over heat a metal spoon but in the this case, it glows brighter.

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The glass bulb is usually air-tight and contains only inert gases which prevents combustion when the filament gets very hot. Dues to the fact that there are a lot of heat loss in this process, other energy saving bulbs that uses light emitting diode (LED) where created.

This is the simplest way the working principle of an electric bulb can be explained, I hope you understand, See video below for further explanation. you can drop your questions below.

Note: the electric bulbs burns out when oxygen finds its way inside the glass bulb or when excess current flows through the filament thus, causing it to melt completely.