Same chapter1 markDifficulty: Medium
The colour of the earth wire in the modern convention is:
Household Circuits
3 marksDifficulty: Medium
What is the function of the earth wire and how does it protect the user?
Original Khojo Papers practice question — not from a past board paper.
Answer
The earth wire connects the metal body of an appliance to the earth. If the live wire touches the metal body, a large current flows straight to earth through the low-resistance earth wire, which blows the fuse or trips the circuit breaker and cuts off the supply, instead of passing through anyone who touches the appliance.
No citable source has been recorded for this record. Treat it as practice material, not as fact.
Explanation
Without an earth connection the body of the appliance would stay live and give a serious shock.
Related questions
From the same topic and chapter, at a similar level.
Same chapter3 marksDifficulty: Medium
State two advantages of a miniature circuit breaker over a fuse.
Household Circuits
Same chapter3 marksDifficulty: Medium
A house has five 60 W lamps and one 1000 W heater, all working together on a 220 V supply. Calculate the total current drawn and state a suitable fuse rating.
Household Circuits
Same chapter3 marksDifficulty: Medium
Why is a three-pin plug preferred to a two-pin plug for a metal-bodied appliance?
Household Circuits
Same chapter2 marksDifficulty: Easy
Why is a fuse always connected in the live wire and never in the neutral wire?
Household Circuits
Same chapter2 marksDifficulty: Easy
Name the three wires of a domestic supply and state the colour of each in the modern convention.
Household Circuits