WAEC 2015 Physics · Question 30

Which of the following statements about a three-pin plug is/are correct. i. The brown wire is the live wire…

Question

Which of the following statements about a three-pin plug is/are correct. i. The brown wire is the live wire. ii. The fuse is connected to the live wire. iii. The earth wire is coloured blue

A.i only
B.ii only
C.i and ii only
D.i, ii and iii

Answer: C. i and ii only

Explanation written with AI and checked against the answer key

Analyze the question: We need to check which of three statements about a three-pin plug (UK-style, used in Nigeria) are true.

Concept: The wires in a three-pin plug follow a colour code:

Live wire: brown. It carries current to the appliance.
Neutral wire: blue. It completes the circuit.
Earth wire: green and yellow stripes. It is a safety wire that carries current to the ground if there is a fault.

The fuse is always placed in the live wire, so that it breaks the circuit before dangerous current reaches the appliance.

Check each statement:

i. The brown wire is the live wire. True.
ii. The fuse is connected to the live wire. True.
iii. The earth wire is coloured blue. False. Blue is the neutral wire, and the earth wire is green/yellow.

So only statements i and ii are correct.

Answer: Option C. i and ii only.

Tip: Remember "Brown = Live, Blue = Neutral, Green-yellow = Earth." A handy phrase is "Brown is Burning (live), Blue is Boring (neutral)." The fuse always goes on the live side.

AI can make mistakes. Report anything that looks wrong.