Why Do Light Bulbs Pop When Switched On?


Why do light bulbs blow once they're switched on?

Mystery Hour Question

Why do light-bulbs blow when you turn them on?

Ellen, Edinburgh


Name: Andy, Waterford, Ireland

Qualification: He's an electronics engineer

Answer: A standard light bulb consists of a little coil of wire inside the glass bulb. When switched on, the electric current runs through the coil and heat up and glows. Because there’s no air in the bulb it gets warmer. When heated, it expands. If there’s a problem with it, the movement when the metal expands causes the fracture.