1. When a live wire comes in contact with a neutral wire, it causes a ‘short circuit’.
2. This happens when the insulation of the wires get damaged due to temperature changes or some external force.
3. Due to a short circuit, the effective resistance in the circuit becomes very small, which leads to the flow of a large current through the wires.
4. This results in heating of wires to such an extent that a fire may be caused in the building.