Answer the following about domestic electric circuits.
Generated by claude-sonnet-4-6 · 2026-06-15 06:50 · grounding rag
Model Answer
(a) The earth wire is connected to the metallic body of appliances (like electric press, refrigerator, toaster). If there is any leakage of current to the metallic body, the earth wire provides a low-resistance path for the current to flow into the ground. This keeps the potential of the metallic body equal to that of the earth, thus preventing the user from receiving a severe electric shock.
(b) Two precautions to avoid overloading:
- Do not connect too many appliances to a single socket.
- Ensure that the insulation of wires is undamaged and there is no fault in any appliance (to prevent short-circuiting).
Source: Chapter 12, Section 12.4 — Domestic Electric Circuits
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Explanation
- (a) is worth ~2 marks: explain what the earth wire does (connects metallic body to ground), how (low-resistance path), and why it matters (prevents electric shock). All three points must be there.
- (b) is worth ~1 mark: two brief, distinct points suffice. Common mistakes include giving vague answers like "use carefully." Stick to the textbook reasons: too many appliances on one socket, and damaged insulation/faulty appliances causing short circuits.