In Household wiring, what is the colour of "Earth wire"?

20172021

In Household wiring, what is the colour of "Earth wire"?

  1. A.

    Black

  2. B.

    Green

  3. C.

    White

  4. D.

    Red

Attempted by 22 students.

Show answer & explanation

Correct answer: B

Concept

Household wiring uses three separate conductors, each identified by a standard colour so electricians can wire appliances safely: the Line (Live) wire carries current from the supply, the Neutral wire completes the return path, and the Earth (Ground) wire is a protective conductor that connects an appliance's exposed metal body to the ground so any fault current is safely diverted instead of passing through a person who touches it. In Indian household wiring practice (IS / Indian Electricity Rules), Live is Red and Neutral is Black, while the Earth conductor is Green — the Bureau of Indian Standards also permits marking it green with a yellow line, matching the internationally harmonised IEC 60446 bi-colour code used for protective conductors.

Conductor

Standard colour

Line / Live

Red

Neutral

Black

Earth / Ground

Green

Application

Matching the offered single-colour options (Black, Green, White, Red) against this convention: Red = Live, Black = Neutral, and Green = Earth (the colour used for protective earthing in Indian household wiring). White does not appear in the standard Indian three-wire colour code at all.

Cross-check

A quick safety cross-check confirms the assignment: if an appliance's metal casing develops a fault (e.g., a live wire touches the casing), the Earth wire must carry that fault current safely to the ground and trip the circuit breaker/fuse, protecting the user from shock. This safety role is why the Earth conductor is given its own distinct, unmistakable colour rather than sharing a colour with Live or Neutral — confirming Green as the correct identification, distinct from Red (Live) and Black (Neutral).

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