Which of the following CANNOT be connected in a lighting sub-circuit?

The correct answer is option 3.

Explanation

A lighting sub-circuit is designed to handle low-power loads such as lights, fans, and small appliances that operate at low current ratings. The main considerations for a lighting sub-circuit are:

• Fans: Ceiling fans are commonly connected in lighting circuits because they require relatively low power (typically 50–100W).
• Lights: The primary purpose of a lighting sub-circuit is to power lights.
• 5A Socket: Small sockets (typically 5A rated) are sometimes allowed in a lighting circuit for low-power devices (like phone chargers or table lamps).
• Geyser: A geyser is a high-power appliance (usually 1000W–3000W), requiring a dedicated power circuit with higher-rated wiring, MCB, and separate earthing. Connecting it to a lighting sub-circuit can lead to overloading, overheating, and safety hazards.

Thus, a geyser cannot be connected in a lighting sub-circuit due to its high power consumption.