Inside Your Socket — Live, Neutral and Earth

What you'll learn

• Electricity only flows in a full loop: out on the live wire, through the appliance, back on the neutral.
• Live = the push: 230 V · 50 Hz in India, the UK and Europe; 120 V · 60 Hz in the USA and Canada.
• Neutral = the way back. It's joined to the earth at the transformer, so it sits close to 0 V — but it still carries current, so never treat it as safe.
• Colours: UK / Europe live brown, neutral blue, earth green-yellow · USA / Canada hot black, neutral white, ground green or bare copper · many Indian homes red, black, green (newer wiring brown, blue, green-yellow). Always check your country's rules.
• A bird on one wire is fine: no loop. You on the floor touching a live wire close the loop through your body and the ground back to the transformer → a shock.
• The earth wire runs from your socket to a metal rod in the ground and to the metal case of things like kettles, irons and washing machines. Normally it carries nothing.
• If a loose live wire touches the case: without earth the case sits at mains voltage and the current goes through you; with earth a huge current rushes down the earth wire and trips the breaker or blows the fuse in a split second.
• The earth pin is often the longest: it connects first and lets go last. Two-pin chargers marked ⧈ are double insulated: no metal case to earth.