Explain the meaning of overloading of an electrical circuit. List two possible causes due to which overloading may occur in household circuits. Write one preventive measure that should be taken to avoid overloading of domestic circuits.
Generated by claude-sonnet-4-6 · 2026-06-15 06:44 · grounding rag
Model Answer
Overloading occurs when the total current drawn by all appliances in a circuit exceeds the safe carrying capacity of the wires, causing excessive heating and possible fire.
Two causes of overloading:
- Connecting too many high-power appliances (e.g., heater, AC, geyser) simultaneously to the same circuit.
- Using wires of very low current-carrying capacity (thin wires) in the circuit.
Preventive measure:
Use a fuse or MCB (Miniature Circuit Breaker) of appropriate rating in the circuit. When current exceeds the safe limit, the fuse melts (or MCB trips), breaking the circuit and preventing overloading.
Source: Chapter 11 – Electricity, Domestic Electric Circuits
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Explanation
- The question has three parts (meaning, two causes, one preventive measure) — examiners award 1 mark each, so cover all three clearly.
- "Overloading" definition must mention excess current beyond safe limit.
- Causes should be distinct — one about too many appliances, one about faulty/thin wiring.
- Fuse/MCB is the standard NCERT-expected preventive measure; mention how it works (melts/trips to break the circuit) for full marks.