Question

In domestic circuit the colour of neutral wire is :

• A. black
• B. red
• C. blue
• D. green

Hint:

Electrical wire color codes are important for safety. They vary by region. {Older common convention (e.g., India, old UK):}
Live: Red
Neutral: {Black}
Earth: Green {Newer IEC / European / Modern India convention:}
Live: Brown
Neutral: Blue
Earth: Green-and-Yellow stripes Since "Black" is an option and often associated with neutral in many contexts where these questions appear, it's a likely answer referring to the older standard.

Answer 1

The Correct Option is A

Concept: Electrical wiring in domestic circuits uses a color-coding system for wires to ensure safety and proper connections. These conventions can vary by region, but there are common standards. Step 1: Understanding the main wires in a domestic AC circuit A typical single-phase AC domestic circuit has three main types of wires:
Live Wire (or Phase/Hot Wire): Carries the alternating current from the source to the appliance. It is at a high potential relative to the neutral and earth.
Neutral Wire: Provides the return path for the current from the appliance back to the source. It is maintained at or near zero potential (earth potential).
Earth Wire (or Ground Wire): A safety wire connected to the metallic body of an appliance and then to the ground. It provides a low-resistance path for current to flow to the earth in case of a fault (e.g., if the live wire touches the appliance casing), preventing electric shock. Step 2: Common Color Coding Conventions Color codes can vary by country and over time.
Old UK / India Convention (still widely found):
Live: Red
Neutral: Black
Earth: Green
New International (IEC) / Harmonized European Convention (also used in modern installations in India and other places):
Live: Brown (for single-phase)
Neutral: Blue
Earth: Green-and-Yellow striped
North America (e.g., USA, Canada):
Live (Hot): Black (or Red for a second hot wire in 240V circuits)
Neutral: White
Ground: Green, or Green-and-Yellow striped, or bare copper. Step 3: Determining the color of the neutral wire based on options and common knowledge The question asks for the color of the neutral wire in a "domestic circuit" without specifying a region. Given the options: (1) black (2) red (3) blue (4) green
If we consider the older convention (still prevalent in many existing installations in places like India), the neutral wire is Black.
If we consider the new IEC convention, the neutral wire is Blue. Since "Black" is option (1) and "Blue" is option (3), and the image circles option (1) "black", it implies the question likely refers to the older, very common convention where neutral is black. Red is live (old convention). Green is earth. Therefore, based on the older common convention (and the circled answer), the color of the neutral wire is black.