What occurs when the filament inside a bulb breaks?

When the filament inside a bulb breaks, the electric circuit becomes incomplete, and as a result, current stops flowing through the bulb.

The filament, usually made of tungsten, is responsible for producing light when it heats up due to the flow of current. If it breaks, there is a gap in the conducting path, which prevents electrons from moving across the circuit.

Because no current flows, the filament cannot heat up, and therefore, the bulb stops glowing immediately.