WORKING OF AN ELECTRIC BULB
• In a transparent electric bulb, there is a thin filament or a very thin metal wire. The filament heats up when an electric current is passed through it. It heats up so much that it begins to glow and gives out light.
• In case a very large current flows through the bulb the filament gets heated up too much and gets broken, the bulb is said to be fused. Such a bulb cannot give light as the path is not available for current to flow.
Invention of electric bulb:
• The first electric bulb was made in 1809 by Humphry Davy, then It was perfected by Thomas Alva Edison.
• In 1910, William David Coolidge invented a tungsten filament which lasted even longer than the older filaments.