In house wiring, three colored wires are typically used: Live (or Phase): Usually red or brown, carries current to the appliance. Neutral: Usually blue or black, completes the circuit. Earth (Ground): Usually green or green/yellow, provides a path for electrical faults to prevent shocks.
(a) Direct contact between the live (usually red or brown) and neutral (usually blue or black) wires will result in a short circuit.
(b) In the case of a short circuit, the current dramatically increases. This happens because the low-resistance path formed by the short circuit bypasses the normal load, allowing a surge of current. The increased current can lead to overheating and pose a fire hazard.